A couple of questions about your journey so far

rankinsect

Why did I gain?

I don't really know, I don't clearly remember a time before I was obese. By maybe age nine I was already turning down invitations to go swimming with my friends because I felt too fat to be comfortable doing so. From what I do recall of my earliest childhood, when I was actually thin, it seems like it was more hyperactivity keeping my weight down than any discipline around food. When you spend all your waking time climbing trees, biking, running, and playing, it's fairly hard to gain.

Why did I start to lose weight?

I actually was not too uncomfortable with my body (although I still don't swim). My main motivation was to be able to do the things I would like to do without my body holding me back. I really enjoyed the outdoors, wanted to do more, but realized unless I lost weight and gained fitness, I would be incapable of doing what I wanted.

Why did it take so long?

Lot of failures. I tended to do all of the common mistakes - being way too aggressive, having no plan for how to maintain, etc. Eventually I just settled into habits. Of all the odd things, I think getting a very needy cat was the most immediate cause of starting when I did. He broke up the routine of my day to day life enough that it made forming new habits easier.