I've been pondering this two things a lot lately. I want to be contentment but I do not want to be complacent in anything.
I think contentment is being happy with what you have, while not denying there might be a need in the future. Jesus says we are to be content with housing, food and clothing. If we have those basic necessities we have all we need to be content. That does not mean we won't need more food, more clothes or a different house/neighborhood.
Complacency is a lazy contentment. A contentment that says, "I don't want anything and I refuse to acknowledge a need because then I will need to do something to meet that need." Complacency denies needs because it deems everything a want. Complacency says, "I have food. I will never need food and I will be content with the food I have. I have clothes. I will never need more clothes. I have a house. I will never for any reason need a different house. So I won't even bother grocery shopping, clothes shopping, or house shopping for any reason."
That might be overly simplistic, and taken a bit too far. We all know we'll need to get more food and we can't wear the same clothes all the time. That is ridiculous.
But so is denying any need we have because we're content with what we have.