In praise of obstinacy (part 1):
The #1 lesson that I've learned from my business experience is that I should trust my own instincts. When I was younger and less experienced, I often deferred to my elders, believing them fountains of hard-won wisdom and experience. What I've discovered (and this should come as no surprise to anyone who has worked in any business organization) is that older doesn't mean wiser, it just means closer to death.
Get this through your head: No one knows what they're doing. Not your boss, not your co-workers, not your professors, not even your parents. Regardless of how sure someone seems of their convictions, if they don't make sense, they're probably full of excrement.
Trust your instincts, and don't let your fear of being an asshole override your better judgment. I did, and it cost me over $5 million.