I was always skinny as a kid (always heard "you should eat more"). Then at 25 I gained everything I should have gained over my life, in about 6 months

A sugar high isn't like a caffeine or nicotine high (yes I do both) at all. Instead its more of a feeling of strong energy followed by the knowledge that you can just continue eating. It is so subtle that it makes complete sense to me why people can binge-eat: you feel like you can't stop and don't want to stop.

The carb crash comes so quickly afterwards, though. 30 minutes of cloud 9, 2 hours of being tired. The last time I had a "normal" pizza or whatever I had the sugar high and carb crash so fast that it amazed me -- and caused me to realize that my WOE is the only one for me.