Which ones have struck a cord with you lately?
Mine are: A large number of men (not every men) will not bother talking to you regularly if they aren't sexually attracted to some extent, even if you're just friends.
Once a friend knows you're interested, the friendship is likely to never be the same again. Even after months/years, even if you take it will and don't mention it again, some people will be funny about it/distant with you forevermore, even if you were friends.
Any close friend can just drop you at any point for no apparent reason. That friend you can talk to every day who you think you can trust with anyone. Yep, they can just decide to stop bothering for mo apparent reason.
There's not always a happy ending. Not everyone 'finds their person'.