[Yugi Starwind]

Okay, I know this may sound cheap and like i'm ripping it off, but this is so true.
Do not fear. Fear is the mind killer. [in other words, for me at least] if you're dwelling on some mistake/screwup you mae and keep thinking about it, things will only get worse. kinda like the whole Karma deal.
===Personal example ahead===
some A**hole of a kid was annoting me to death last year in HS. i kept saying each day[to myself] "don't let it get to you", but I did. It got worse because i thought about "what if it does get to me?" and "what will I do?" which pretty much lead to me having a bad year emotionally.
==end example==
If that doesn't help, then this will have to do:
Everyone that comes into your life has a purpose. you're either in their life to make them happy, or they're in their life to teach you some kind of lesson.
==another example==
today was my g/fs B-day. I was being a cheap***[but loving at the same time] by making her a tribute video set to "glory of love" and using photos from past events w/ us. I sent it to her last night, since she was kinda upset, and when she watched the video, she pretty much just went into goo. started crying happy tears..saying "I love you"..like it was the biggest thing anyone had ever done for her.
==end example==
the lesson here: your life can change another for better or for worse.

that's my 2 cents.