Yes, I have this problem and yes, it is totally annoying.
But, no, I can't really help you... I can't even help myself...
I have been thinking lately that it might need to be a goal perspective thing. By working on **I WILL acheive ..... because of/then I'll ......** instead of just randomly allowing myself to do *whatever*, I might actually become great at something, instead of just "good at everything".
I'm not great at setting goals because I jump between interests too easily. So I am going to work on my goal setting and see if that will allow me to focus better... It seems like a long shot but I'm willing to give it a go.