this and that

I heard something on the radio this morning, a story I don't remember any details about, but it used both the words "contentment" and "complacency," and since then, I've been asking everyone (well, three people):

How do you tell the difference between contentment and complacency?

I'm not asking for the dictionary definitions of them--I know what they both mean--but both from the inside (in other words, if it's yourself and your feelings you're talking about) and from the outside (if you're talk...