I think there's a danger of drawing a line too cleanly between pleasure and happiness, though. A happy life will include pleasure and the pursuit of pleasure, it's hard to imagine one that didn't.

If somebody thinks they'd enjoy a small piece of cheese, eats a small piece of cheese and is satisfied, that's not really a problem. It's when they keep eating, even to the point where it actually becomes unpleasant, that the problem arises. The devil's advocate could also ask where contentment ends and complacency starts. An olympic gold medalist is likely to be very hard to satisfy, how do we judge that lack of contentment?