I think this is really interesting! I am the same as you, where I can get very bored very quickly. I will put together an entire regimen and diet and be super motivated for the first 3 days, if Im lucky maybe 14 days. This might have been key, though - Being "knee-deep in another obsession" to occupy your brain. Making weight loss a passive habit, and not necessarily what you need to spend ALL your energy on. +1 for habit building and longevity!
The numbers game is terrifying - We are minimizing people and our relationships to a single number defined by a very specific algorithm.