Hovering over things doesn't work

So I have had my MacBook Pro for a solid 1 1/2 years, and I am very satisfied with apple. However, recently my macbook started doing this thing, where when I hovered over something (say, my dock), it wouldn't think im hovering over it until I clicked it. So basically, when I go over my dock and put my mouse over system prefereces, it doesn't display the little bubble that says "system preferences". This is extremely annoying when playing games or watching videos, nothing works fine. Tried restarting, still didn't work.