My ex-gf just got married - how should I not let this affect me?

My cousin has this problem right now. His high school sweetheart just got engaged to someone else, and he let it tear him up. The only remedy for a broken heart is someone else to fill it. I know that's not necessarily what you want to hear... but trust me that if you go find someone else to pay attention to and care about, you won't think about this girl at all anymore.