An unconsidered life

I'm trying to find a quote about "an unconsidered life." I cannot for the life (heh) of me remember who said it, but I'm pretty sure it goes something along the lines of "An unconsidered life is one wasted." Does that mean that someone who goes through life in a carefree manner is wasting their life? Is that why we're put here? To walk around in a state of perpetual deep thought? If you don't walk around considering everything, then are you somehow less worthy than someone who does?

Don't get me wrong, I'm all for being thoughtful, but I just don't want to think that I am wasting my life because I place an extremely high value on being happy. I think that if you're happy, then everything else will fit into place. Of course, everything has to be more or less in place for some people to be happy...you can define what "in place" means for yourselves. I suspect that my life is more like Charles M. Schulz's, who said, "My life has no purpose, no direction, no aim, no meaning, and yet I'm happy. I can't figure it out. What am I doing right?"