I tell myself, like someone else in this thread mentions, that my fixation on diapers started with a simple curiosity, transformed into obsession over time, and, with wearing for the first time as an adult, turned into a practical realization.
Specifically, I became curious as to why older kids/adults wore diapers when I noticed a childhood friend wearing a diaper to bed. (think 9-10 years old, third-fourth grade) When I learned about the causes of bed wetting and incontinence, the use of diapers was justified, thus I became curious as to what it felt like to wear and use a diaper.
My father was somewhat strict and traditional. . .for example, he did not like anything that seemed remotely homosexual or un-american. . .so I just kept my thoughts to myself without wearing diapers for about 15 years. Those 15 years were when it went from curiosity to obsession. When I was not focused on school, online games, or other hobbies, I was thinking about diapers, fantasizing about wearing them or trying to rationalize or my desires. I would even say that I obsessed over other things in order to avoid thinking about diapers. I knew it was "abnormal", but the more you try to forget, the more it comes knocking.
Only a few months ago, at the age of 26, did I get the chance to wear a diaper and experience what it was like. That is when I realized there really wasn't much to it. They serve their purpose. If used properly and carefully, they do not leak and offer convienence and comfort. ( It is a comfort to know that I do not have to hold it and be distrseed over if I will make it to the bathroom in time; however, I have not had a real accident in years.) To the general public, I am just somebody with a medical problem. If anybody suggests otherwise, they are an inconsiderate ass and I do not need to associate with the anyway. Nobody would know of my desires, except for maybe my immediate family and my doctor(s).
Thus, I realized that diapers served a practical purpose with no real downsides, besides the awkward situations around people who do not wear diapers, but it is not their fault. It is just the social norm after generations of potty training.
Anyway, that is my somewhat abbreviated story. . .
If someone wanted to get Freudian with me, you could say the divorce of my parents, early potty training, and being jealous of the tender loving care my siblings received afterwards, lead to or at least contributed to my desires. I wanted my mother's tender loving care, I noticed my sisters getting that care while they were in diapers, therefore I wanted to wear diapers. But that is only one take on my life. ()