What drives us anyway?

Isn't it odd that we often let the strangest things drive us? We put our foot down and say - firmly - that we believe in THIS or THAT (and add in a "by God!" for emphasis) only to buckle and change our course the minute there is any resistence. I need to concentrate on the things I can change, the things I can control - but I don't. Instead, I feel up to HERE with frustration about the things that are completely out of my hands... maybe it is because I feel so strongly about THIS or THAT and when the wind shifts, I am completely deflated. I called it "disillusionment" to my friend sharing drinks and laughs one night... That's it, isn't it.