This isn't actually a bad thing, it's called being a multipotentialite. There's a TED talk on it.

The 3 good things about being this way is:

• Idea synthesis - where your random bits of knowledge intersect from different hobbies, you can create new solutions and ideas by cherry picking from different fields of information.

• Rapid learning - Being "new" at hobbies all the time means you can usually pick them up faster. It ties in with not being afraid to try something new solely based on the fact it interests us. Some of the skills end up being transferable anyway which means sometimes new hobbies aren't really new.

• Adaptability - Taking the information we have and using it where necessary, even if it's in an entirely different discipline or hobby.

I don't mind being this way. I think some people see success as finishing; as in I finished this project, look at what I made or did and give me praise. That's discipline which is a good thing. But also, I started this project, I learned a heap but now I'm done is totally fine too. At the end of it all if you learned what you want and it no longer interests you, you're under no obligation to continue the hobby.