I'd be here all night if I were to list the hair disasters that have befallen me through the years!! 
Where to start... as a teenager, my mother's hairdresser friend cut my hair and as soon as she left, I was inconsolable as despite it being the 80's, I had no desire to emulate Rod f&@king Stewart. As my mother was also a hairdresser, she tried her best silk purse/sow's ear magic, but she couldn't save this one.
Once that had grown back, I fancied a perm so went to a salon which fried my hair so much that I had to put baby oil on it to stop it looking like cotton wool... DM combed perming solution through it, so I still had candy floss hair, only not curly wee frizzed to fuck, and the hysterics stopped. DM saved this one.
I cannot begin to tell you all how many times I have stated "just a trim" - I may as well have spoken Swahili for all the notice that was taken. I have paid very little and paid a lot, same result 
. DM sometimes saved this one.
I once treated myself to the salon director, thinking he would replicate the cut shown in the picture I clenched in my nervous palm. Reader, he did not. As my face fell and tears filled my eyes, he said, and I quote, "you've moved the goalposts". Had I a goalpost to hand, it would have made a nice perch for his arse. Of course, I paid, but passive aggressively didn't leave a tip 
. That'll learn him! I ran straight next door to the wig department of a department store, whereupon the sales lady took one look at my new do (and foaming mouth) and advised I wait for it to grow down a bit, but couldn't see what the problem was as "it looks lovely". Small mercies, but I was having none of it. Like many others here, cried buckets. DM couldn't save this one.
The world of colour has provided much mirth over the years... I fancied a change from blonde to red so paid a small fortune to go the organic route. Straight up organic tears as I could see the colour darken before my eyes, but thought 'she knows what she's doing'. Reader, she did not. I left the place in shock with a dark auburn hue. And yes, I paid and tipped her. I remember looking in the mirror and thinking 'Christ, it's my evil twin' 
. I had to steel myself to go back and say -fifteen washes later and the water's still running red, wtaf- 'can you do something with this, please?' Sigh. DM couldn't save this one.
The crowning glory (yes, I know) has to be in my student days when I first decided I wanted to try a wash-in red shade. I had heavily highlighted ie bleached blonde hair, so those of you familiar with the basics of colour combining will know that yellow plus red equals orange. Yep, orange. Lasts 6 washes, it said. Reader, it did not. 6 months, more like. And even better, I had splodged it on both sides of my head to begin with and realised even then that it looked a bit dodgy, so tried in vain to wash it off with, I kid you not, half a bottle of Fairy Liquid. Didn't budge. I looked like a deranged piebald donkey. DM tried her level best to sort out the colour, but nothing could be done, so she suggested I bite the bullet and cut it all off. Yep, it was that bad. So I did, and cried for days. I used to dream It had grown back, only to wake and realise nope, still fucked. DF asked me "what the hell have you done to yourself?!", thus providing much solace and comfort to my traumatised self. DM couldn't save that one on either level.
So to the present day. Lesson learnt? Overall, yes. Had a bob for years, loved it as they couldn't fuck it up, but eventually tired of it and grew it long. I now just wash it and leave it the hell alone. It's long, thick and wavy, no need for perms or straighteners or bad dreams, or indeed living hair nightmares. DM would always console me with 'it'll grow back!', and reader, it did. DM saved this one, bless her endlessly patient heart. Love you, Ma! 