LEARN FROM LESSON?

sorry that i'm posting something real private... which i have no idea how to solve it out *although it's doesnt really related to me but one of my close fren.... the situation is so much similiar to my case which happen a year ago~ which i fear it might happen again....

now here's a question.. do we learn from lesson.. or we just repeating it and move on... i mean everyone study HISTORY coz we need to learn from the past .. mistake and what so eva... but now what... coz human are always like that.. TALK IS CHEAP... i know i cant judge... coz i did ask myself..what if i did the same mistake again.... maybe i cant even forgive myself... so what again.. we still live happily after a while... and move on...

SO DO PPL LEARN FROM MISTAKE?