I agree with living in the now, but where I seem to differ in my view from others on here is that posting one thread, once, in AIBU doesn’t constitute in any way living in the past.
Life moves on, and it’s fair to say that constantly looking back, pining, longing and regretting is self destructive and I agree that if someone is doing these things, then some form of professional help might be appropriate. However, you also can’t live solely in the here-and-now either. I think for the most part I have a good balance, to be honest, in some ways I perhaps veer more towards not thinking about my past because some of those memories are painful to me.
But sometimes memories or flashbacks or thoughts will pop into your head unbidden - when you go to a place you went to once, or hear a song, or something like seeing a thread about clothes from the early 2000s 
and I don’t actually think it’s healthy to insist they leave your thoughts immediately and inform your brain that they are not welcome here, only memories from 2018 onwards are allowed here thank you very much! Aside from the fact you can’t do this, repressed memories generally come out in other ways when you determinedly decide you will NOT let them in.
@Namechange466 I’m certainly not trying to shut anyone down, but I am entitled to explain that they are not the same things. For one thing, I was never bullied for my weight - I only really started to put weight on once I had left school. For the most part, my role was Fat Friend. I would console my friends and counsel them through their relationship problems because there was no chance I’d have a relationship so I was ‘safe.’
If I see someone say they don’t understand the point of the thread one more time though, I promise I won’t ‘rage’, but I will confess it’s mildly annoying when I’ve explained, over and over. And others have answered, and explained. And others have shared their experiences and we have talked and we have processed and we have discussed. And still some people come on just to say ‘but I don’t understand.
Maybe, you don’t have to? There are many things I will never properly understand but it doesn’t mean I have the right to inform others they should not share their experiences, or talk about them, or try to make false comparisons by, say, telling someone with agoraphobia that I know just how they feel as some days I want to stay in bed too. It is sometimes right and appropriate to tell people - actually, that is not correct, they are not the same things at all.
Of course, some people never take being corrected well and I do think that’s really where the hostility has come from. I have read back through my posts and I have not once ‘raged’ 