Oh yes, I regret a lot of my past behaviour. The way my past self thought, wrote, and talked to people, including here on SF, is hard to understand now. My first post on this account 8 years ago was titled "Yo whatup whatup whatup"...

I was overly concerned with my privacy at the time and tried to make people think I'm an American...in the cringiest way. In a thread about...I think it was about what the point of living is if you don't believe in God, I was condescending and oh so proud of my newfound conviction that there's no free will or afterlife. I've written arrogant things and I've been a taker much more than a giver when talking to people on here, not to mention off site. I wish the edit function didn't have a time limit, I would go back years and edit so many posts! So many of my diary entries on here...why did I write that? Why like THAT? I'm glad many of my past internet personas are deleted and forgotten.
Increased self awareness is both a gift and a curse.
That being said, I don’t cringe over these posts. I instead use this as an opportunity to practice self compassion and give myself some feedback on how to respond more effectively going forward. I have historically cringed over old journal entries, to the point that I stopped journaling at all. It was too demanding for me to figure out how to please future me.
I like this perspective. It's possible to look back on these old posts and be happy that we've grown and no longer think like that. The best way to avoid the cringe is to just not read your older posts, because pretty much no one else will. But it's good to remember your past selves and how much you've changed, and why.