When it comes to regrets I'm like Anonymous:
NEVER FORGIVE! NEVER REGRET! I'M RELLIK SAN! EXPECT ME... to do something incredibly stupid at some point.
As for things I'm proud of: The first gaming motherboard I researched and bought, I have it framed and hanging on my wall, seriously that thing served me well for a solid 7 years before I upgraded it.
My fine art degree, whilst mostly useless in the real world, I'm hella proud of it, I worked out, covered subjects my professors had rarely seen for essays (my personal favourites are The Use and Merit of Pop Art as Propaganda During the Cold War(or Who's the Worhol of the USSR) and Traditional Modernity: The Ancient Styles Informing Modern Artists: VS Edition (Hokusai vs Amano).
But as silly as this seems, the thing I'm most proud of is not doing the thing I normally do by this point: Fuck up my current relationship. I have a history of being like a relationship vagrant, a serial cheat and even dropping girls like a lead weight when I was bored of them... then I chose to stay single for a while, then I met the love of my life, and despite temptation dropping in my lap 100 times and more, I've never felt the urge to return to my old ways, because I love the hells out of her and 3 years into this, I know for a fact I want to spend the rest of my life with her.
I don't regret those past choices of mine, I wouldn't say I'm proud of them either, I was an absolute shit of a person, but they shaped and informed me as part of who I am now as a person and I'm a much better person for those experiences.