Ooh... That's tough
Probably my younger self. I've done some stupid crap in my life and if I could just tell my younger self to say a different thing or not do something that would have saved me a lot of trauma.
But then again, my mistakes are what make me who I am. My experiences have guided me to this moment. And even though this moment kinda sucks, I think one day I will be grateful for the things I've learned.