Most of my regrets revolve around wishing I'd made more effort at school, both inside the classroom and out.
I regularly do thoughtless stuff, so in that sense I regret not putting more thought into shit.
I also heavily regret that encounter with that lass, where being the girl's blouse I am, I turned around the wrong way.
Many a night do I lie trying to get to sleep, thinking, what the f**k would've happened if I turned the other god damn way around. For something that's such a small thing, it could've made all kinds of difference, and that is why it bugs me. It's going to follow me til the end of my days.
And that kids, is why you should make it your rule to regret DOING things, rather than regret NOT DOING them.