I have a hard time finding long term hobbies and interests

I've had several hobbies throughout my life, all of which I've eventually burned out on.

Horseback riding, writing, drawing, violin, ice skating, graphic design, clarinet.

The only ones I actually got into because of an initial interest were writing, drawing, ice skating, and graphic design. I liked writing and drawing probably from the time I was able to do them, and they just gradually fizzled away sometime in high school. Ice skating was a very short-lived interest I had as a kid after watching a figure skating show, and I only did it for about a year. I had a graphic design class in school and never really messed with it again afterwards, though I'll admit I think that one might still be fun, but I just don't remember how to do any of it.

I got into both clarinet and violin because I didn't want to be in choir (my school required a music credit) and just picked the instruments my parents had played in school. I had fun, but it was basically just for the class and a way to kill time. I did get pretty serious about playing violin for awhile, but then my interest just completely burned out almost overnight. I think the competitive nature of high school orchestra class was just not for me (my music teachers were always extremely serious about perfection and being ultra competitive; I just saw it as a fun pastime).

With horseback riding, my family was always very huge into it and I was pretty much born into the horse world. I was never pressured into it, but I think I wanted to have that in common with them, since they are HUGELY into it. I had a bad fall that left me seriously injured in my early teens, was pretty scared for a long time afterwards and never truly got over it, and once I began driving, my interest really started going away. I still wanted to have that interest in common with my family and still did it, then stuck with it because I couldn't seem to keep other hobbies. I finally quit this year after over 20 years due to A) being extremely burned out, B) always being anxious about getting hurt in a fall again, C) having difficulty juggling it with my responsibilities, and D) I just bought a house and cannot afford to get hurt, plus could use the extra money towards that.

Sorry for the book, but is it normal for hobbies and interests to come and go like this? It seems like a lot of people have at least one thing they are very passionate about and stay that way with for a very long time. It seems that I just go through "phases" and my main interest always seems to be whatever is going on in my life at the time. For example, right now, it's all about house stuff and how I'm going to decorate my house.