It's fair to say everything in life is cyclical. One can try to force things or just ride out the cycles. I heard some good advice a while back from my son's karate coach. When interest wanes it is usually better to alternate between slow and fast instead of stop and start. It kinda keeps us from going all-out. And I certainly tend to go all-in fast, get immersed, and often can get over saturated. After putting less energy to things for a while that were all-consuming, drive and motivation often return.
Just some thoughts