principle vs. taste
"Don???t choose your battles"
I've always liked Thomas Jefferson's comment to the effect that one should stand firm on matters of principle but be extremely flexible on matters of taste.
De gustibus non disputandem.
What's most difficult to always keep in mind is that every individual has different incentives. What appears to be a totally insane decision based on the mutually accepted facts usually turns out to be a difference in the incentive profiles in each person's awareness. Of course, that awareness is always subjective and one person will totally over-look concerns that affect him, which to someone else may seem obvious.