AIBU to wonder why the hell my mum was obsessed with the water bill?

The more expensive bit of the shower is heating the water.

But why should her long hot bath trump a decent shower for OP? Barging in when your child is going through puberty is so batshit.
Perhaps she could have had a long hot bath every other day and OP could have had a longer shower on the none bath days.
Children are people too but some parents treat them little better than animals.

I did sort of mention it in a round about way over the years, for example they used to think I was stupid for bathing my children every night and putting them in clean pj's. They couldn't believe they had clean uniform every day so they remained convinced they were right and hadn't done anything wrong.
We are NC now for other reasons.

That just sounds like out and out control to me OP. I’m sorry you lived like that.

If she liked a long hot bath then maybe she didn’t want the water ‘running out’ before her bath? I’m so ancient I remember this being a big thing if the shower ran off the water boiler. There was only ever a certain amount of hot water available at any one time.

I was thinking about this the other day too. We were always made to share adventures calendars and take it in turns to open a door as if they were a precious and rare commodity that cost hundreds of pounds. Imagine my surprise as an adult to realise you can get them for a quid in any supermarket.

@FannyFernackerpants have you tackled your parents about this?

I knew kids at school who were treated similarly. My mother was enraged, but neither she nor anyone else raised concerns. This was in the 70s. I think the view then was that abuse was beating - and this type of abuse was not recognised as such. But what decent parent fails to replace worn out school uniform when they’re smoking? And sending your DC to school dirty and smelly should raise alarms at school.

Maybe you used to take too long and she just wanted to make sure you hurried up and got ready for bed/school?

Her behaviour was not ok but in our current house the hot water is not constant (as in our previous house). Only two of us can have long showers without the hot water running out for a while until more gets heated up. I do remind my children of this occasionally.

Oh and @toomuchfaff I'm in my 40's and this still bothers me. Raising my own children has made me realise how rubbish some aspects of my childhood have been.
It is natural to look back and think 'why on earth did they do that'.

I was limited to 1 'bath' (about an inch of water in the bottom) per week, despite living on a farm and being covered in all sorts on a daily basis.
Looking back my parents bathed daily as they needed to for work (had jobs outside the farm).
Apparently being bullied for smelling every single day at school was no reason to have a bath, I just needed to get a thicker skin.
My supposedly white school shirts had black tide marks around the collar permanently and my school trousers had holes in the inner thigh (they would not be replaced until the summer holidays even if the holes appeared in January). I was told we couldn't afford these things, it was only as I got older I realised that any spare money was going on the 30 cigs a day my mother smoked and a couple of bottles of whisky they drank through the week.
I understand that parents should enjoy themselves and a few drinks at night is a nice way to relax but I couldn't enjoy it knowing my child was dirty and in inadequate clothing- some people really shouldn't bother having kids and it sounds like your mother (and my parents) were the people that shouldn't bother!

In summary (and there's much more), it's:
the shock of realising that your own formative years were not normal;
the confusing discovery that the parents you relied on were not reasonable;
the agonising self-examination over whether you 'deserved it';
the bewildering effort to understand why they did what they did (or didn't).

Onlookers sometimes fail to appreciate that children have no detached perspective, no wider experience against which to judge their own caregivers. A child's world is formed by the adults in charge: it's all they know and it forms their identity, their understanding of who they are and their place in the world.

Once you realise your childhood was not as it should have been, you can't go back and have a different one. You're faced with re-evaluating everything you know about yourself. This often involves questioning many details like the one OP's raised here. It can be intense and quite upsetting, particularly as people usually need to separate the good and not-bad elements from the grim.

Some people really do need to take a stance that it was all absolutely terrible, their birth family are monsters, and reject their entire childhood. That's an extreme position because it also means rejecting themselves, the person resulting from that childhood. It can only be done successfully with intensive psychiatric support. The rest of us are luckier, if you like, but it still means picking everything apart as the issues arise.

OP’s mother’s behaviour was not frugality. She was limiting her child’s showers obsessively but having daily long hot baths herself. It was nothing to do with money and everything to do with controlling and restricting her child.

It isn’t that OP has issues with her mother. It’s about the way her mother treated her, and connected to the abuse that has led OP not to speak to her mother for the last 7 years.

Do you have to be so unpleasant?

So you're 26, and you're still looking back and wondering about why your parent did something in your childhood. What are you expecting to gain from this ? Some form of closure? Or another reason to hate on a parent that your hating for many other reasons? Either way, what difference does it make to why she did it?

I suppose what I'm trying to get to is, life's too short to spend your time looking back wondering why someone did something. Learn from it, and shut the door on it.

Yes, both of these.
Like my father not letting friends phone us in case emergency calls were trying to get through.

Maybe you were on a water meter so charged by usage?

Thank you. I am working on it- that’s just one element and I thought it important OP knew what she experienced was abusive. Frugality was an excuse.

My parents are both dead.

Bloody hell. I'm sorry you were mistreated like that. I hope you've been able to recover. And I hope your parents are nowhere near you now.

Yes exactly this. We were also barred from using toilets when out and about so would try to drink plenty before we left the house but inevitably would be absolutely desperate for the toilet AND thirsty. I swore blind my children would never ever be deprived of fluids or toilets. You are right, the thirst would be physically painful. I have never been close to that thirsty since

The shower thing was obviously just the tip of the iceberg in terms of her poor treatment of you.

Did yours keep you dehydrated when out because they didn’t want the bother of taking you to the bathroom? Mine did that. I still vividly remember that thirst. It was physically painful.

Yes that is unhinged.
My parents would line us up in the hallway in our towels, turn on the shower and we’d get 2mins each. They’d stand with a stop watch and yell “next” so the one in would have to hop out as the next one hopped in. The water ran for 10mins total (5 of us). They also would “issue” us toilet paper squares. We would get 20 squares a day. The toilet paper was locked up. As was all food in the house. Hot water was only turned on in evening for showers and dishwashing. Summertime they’d turn on the lawn sprinkler and we’d get a scrap of soap to pass around our “shower” was in the garden in our swimming costumes.

We weren’t on benefits, or poor.

I had a childhood of neglect and abuse. So what you describe seems like an element of child abuse imho.