The maniac raises to $6 on the button. The small blind folds and you call.
You check and they bet $10. You have top pair and a good kicker, and raising would only scare them off their bluffs, so you call.
You check, they bet $25 and you call.
You check and they bet $60. A call costs $60 for a final pot of $203, so it needs to win about 30% of the time. You've seen this player show down three bluffs tonight, so you call. The same line from a rock would be an easy fold.