I think it really depends. Loss and grief can teach us things, the problem is, we may not want to learn those things. Ignorance (or rather, innocence) can be bliss, but do we want to be ignorant, aren't we always trying to learn? Grief I have experienced has made me into a different person, in some ways better, in some ways worse, but defiantly different. Its a cursed gift that both takes and gives at the same time. It seems like the more you learn, the less you can do with what you learn. Maybe wisdom is understanding how to glean happiness from that. I've always struggled with this dichotomy.