My experience with hobbies over the years have been very similiar. First my interest will be piqued by something I see or read. Then as I learn more about it, I start to get psyched. I start buying supplies, tools, books, etc. And then after about 5 years, the interest starts to wane and I go on to something else.
Over the past 20 years I've been through woodworking, gardening, gun collecting and now modeling. I've learned quite a bit about each one and have gotten pretty proficient at woodworking and shooting. But now the tools and guns mostly just sit around for me to look at.
As for my modeling, I have been in a funk for the past 6 months. I'll dabble a little and then get bored or frustrated and walk away. I've decided to try something different and have a Fine Molds X-Wing on the desk now. Hopefully this will get the juices flowing again. If not, maybe this is just another hobby that's run it's course for me. We shall see.