I regret that I never made as much time as I could have for my dad when he was around. Knowing how much simple texts calls and emails would have meant, my consistent failure to respond promptly and contact regularly will always be a regret. I hate the idea that he might have thought I didn't care, rather than I am just lazy/thoughtless.
I regret clicking on this thread on a Monday morning. But to echo what you said, I wish I had hung out with my dad more when he was alive. Things happen, spend time with your loved ones while you have them.
I'm really grateful to a cousin for pointing this out to me when I was 17 or so. I was at a family wedding, and he asked me if I was going to dance with my mother. Being the self-conscious teenager that I was, I told him I wasn't planning on it. His response was, "Well, you know, she isn't going to be around forever. One day you'll look back and wish you had more time with her."
I think it's important to become your own person, and you need to spend time away from your parents to do that. But I make sure the time I spend with my parents is quality time, and I don't waste it texting or whatever.
One thing I've heard is that the biggest regret most men have at the end of their life is prioritizing work over time with their family. I constantly need to remind myself of this, and I think it is something that other people on HN need to remind themselves of as well. I notice that a lot of companies try to play off the existential fear of being forgotten when we are gone by telling us we are part of something bigger than ourselves. I think that expecting the work you do at a company to create any sort of meaningful legacy is foolish.