A co-worker got a promotion over me
Aw man. Who has been working there longer, you or the co-worker?
me 
Did you receive any sort of feedback as to why you might have been passed over?
It was kinda bullshit. Everyone things the guy is kinda dumb but, goign to lunch with your hiring manager 3 times a week has its perks.
Boooo! Yeah. Might be worth chatting with HR to see if there are any pointers you can get so maybe next time will go in your favor.
I'm thinking its time for a new job.