It sounds to me like you have become bored with your shooting regimen because it isn't challenging. Growing up, I used to shoot at a lot of junk; cans, bottle, cans/bottles filled with water, fruit etc. but after awhile I realized that hitting them at standard distances was no challenge. I also went through the phase of rapid fire and then realized that shooting fast didn't matter if you wern't hitting anything. Since then, I primarily shoot at paper or cardboard targets. This allows you to actually see the results of your efforts. Very few people can shoot to the potential of their gun, so the challenge is always there. If you happen to be one of the rare few who gets to the point where you can consistently shoot to the potential of the gun, then you move the target further away. Another method to spice things up is to introduce a timer into your shooting. Hitting a target becomes much more difficult when you have to do it in a small amount of time. And again, since you will never be able to do it instantaniously, the challenge is always there to do it faster. For variety, you can also add a draw from concealment.
Then of course there is competition. I found that when I started competing, that my recreational shooting changed to reflect what I needed work on; which was revealed in a match. A lot of people who think they are pretty good are humbled when they have to perform under time constraints, under rule constraints, in front of an audience, where every shot counts.
Skunkabilly is on to one of my faviorite plinking targets; if you have some wide open space to do it in. I love to toss a ball out in the desert and start shooting at it. As you hit it, it rolls and bounces further away. The farther away it gets, the more challenge in hitting it. One of my shooting buddies and I compete as Skunk suggested. We throw out a ball and try to shoot it out from under the other guy's sights. As the ball gets out of sight, we walk forward and try to be the first one to see it again and put a hit on it. This usually results in some long range shooting. Most balls hold up for hundreds of shots, depending of course on what you are shooting it with. Rubber type balls will soak up a lot of lead. We often use golf balls; a guy I work with lives on a golf course and picks them up by the bucket full in his yard. Hitting a golf ball way out there with a handgun is a big thrill for me. Using my ARs it is also fun, and I think valuable practice. After zeroing, most people have a good idea where their rifle hits at let's say 100 yards, maybe 200 yards etc. But where does it hit at 10 feet ? What about 25 yards ? With a golf ball you have to have precision shot placement. If you have been satisfied with center of mass hits on a silhouette, you are in for an education.