Tatiana: "It's all about me" = I'm the center of the universe

Talgat: ...THAT sumS me up.

When someone describes behavior that's characteristic of someone you know quite well, it's common to use "yep!" which is a form of yes that means "oh, you don't have to tell me - I know him only too well!" Then we often follow that up with an unstressed "alright" at the end, which indicates that the speaker isn't about to argue with you because you're 100% correct in your assessment: A: Tom's getting a pet lion? He has small children. Is he crazy??? B: Yep, he's crazy alright. It doesn't surprise me in the least.

Улий, спасибо за корректировку и за интереснейшее объяснение! Придётся не раз перечитать ☺
А It's about me правильно было бы?

Правильно, но не идиоматически в этой ситуации.

Uly, thanks. Initially, I wanted to make it "sums me up, then I changed it to "sum me up". It was a bit tricky.

You should trust your instincts, your English is good 😊

I would say "Doing blah blah blah... that (pretty much) sums me up.