How long can I stay?

Why is it so hard to stay on the new endeavour?

It seems like I am lack of staying power with any endeavour.

I started with playing guitar, enrolling for a guitar class. It started with a blast.. very cool but it didnt stay long, the interest faded as times go by. And, I had abandoned it.

Now, I found another cool activity. Kickboxing - "Burn ur fear into power".. I am looking forward for each class but I doubt on how long I will stay this time.