When someone says something is a discipline, it means it takes hard work. Art, with all its subdivisions (drawing, sculpture, painting, photography, collage, etc) is a discipline.
I've heard people say over and over, I want to make something but just don't feel inspired. You won't grow or make much if you wait for that to happen. That's where the discipline part comes in. You have to set a priority and make yourself do it...go draw something, sort some supplies or something to get rolling. The inspiration has to find you working or it finds somewhere else to go. I firmly believe that.
That doesn't mean that one of those wonderful moments won't hit where an idea, fully-developed and ready to go, won't drop into your brain. Treasure those moments as they are rare. And get right to it! It's been my experience you need to hop on that idea as soon as it hits like that. They seem to fade away if you don't grab them.
Art looks fun. It can be fun but that doesn't mean it doesn't require work...a class, practice, exercising those skills are the only way to get better.
So, just like golf, you've got to play more than once a week to get better. Set a time, and do it. Even if the thing you make is awful and you want to bury or burn it, keep on. That's one step closer to the next level of your artistic growth.