Well, OK, my story is the same, but different than most have described. I've told it a bunch of times and places, so if you've heard it before, please forgive my repeating myself.
For me, it may have begun while I was still in diapers, but the mold was definitely cast when I was taken out of them. Perhaps it was the attention I received during changes, or maybe just that silly sense of freedom a toddler has, when they're just running around in a diaper, poofy plastic pants, doing what toddlers do. The next thing g you realize is that they're gonna make you start using the toilet, and so the training starts! The troubles is/was, in my case, my older siblings were assigned the task of introducing me to the world of the toilet, butt wiping, etc. I really think I understood it all, and as a fairly smart kid, I caught on quick. Trouble is, my brain wanted to regress to those carefree days of running around in diapers. Other kids in the neighborhood were still in diapers, as were some of my cousins, so the reminders were just always there.I couldn't act on any of it, but I knew I was different because everybody else seemed to assimilate, except me. It was all cloth, back then, so there was really no way to wear/use diapers, without it being too obvious. Had I been able to act it out, MAYBE I'd have graduated myself out of them, but, instead, they were to become my biggest secret, and I had secrets! By 5 I was trying on the plastic pants I once wore, and it just felt too special to give up. I had a rather normal life, otherwise, but once I hit 12, the diapers were merging into my sexuality. Imagine how hard it was to actually have sex with a girl, compared to how easy it was to save some money for Gerber's, lubricate them, and have some of the best solo sex imaginable, all the while imagining them to be a girlfriend, and one that didn't complain, or place silly teenage demands on me. Honestly, from that point on, it was just a matter of keeping my secret just that, a secret.
In some ways, early on, I kind of hoped I'd grow out of it, but as I got older I realized my brain needed this special something that had that magical quality of giving me durable and recurrent erections, and I found less and less reason to fight it. Marriage, kids, jobs, life, etc. Nothing g has gotten in the way of me having this continued fun and comfort, of something so child-like, and, yet, so me...