What I have learnt in the past from experiences and how I can stay happy. The three golden rules:
1. Being a guy's friend is the best.
(They're good friends, seriously. Until they tell their girlfriends your secrets so just shush up.)
2. Never assume anyone likes you, even though there are signs. :S
(Everything just becomes awkward for you and you get paranoid about everything.)
3. Push anyone away if you get close.
(It will just end in unhappiness)