As for the pushover part, since I hate arguments, you might get away with pushing me a little. I love spontaneity. Think how utterly boring life would be if everything was completely predictable. Spontaneity is the spice of life. Without it, life loses quite a bit of flavor.
Stability gives a sense of security and peace.
I just think that there must be a balance between the two, and more often than not, people lean too heavily on the side of stability. In other words, I think spontaneity is woefully underrated. I love going out and doing things I've never done before. The memories we treasure most are not the memories of routine days, but the memories of unique days. Heck, people don't generally even remember routine, boring days.