[ambivalents]

I don't actually think that's true. If you're making positive lifestyle adjustments (and not just going on a flash diet hoping for instantaneous results), then there really isn't a "there" to go back to. You gradually adopt healthier habits, replacing older ones, and they become learned behavior. Your tastes change. Your stomach gets smaller. Not to mention your "set point" average weight will decrease and your body/metabolism adapt to living at a lower weight.

This sounds a little vague, apologies. I've done many diets (paleo, keto, South Beach, etc.) and nothing worked. So instead, over the course of six months I gradually gave up sugar, I gave up meat, I stopped eating snacks between meals. I still ate delicious foods, but in smaller portions. Only sweets I had were fruit. I kept my exercise the same (3-5x/week).

I lost 15 pounds and have kept it off. Have no intention of gaining it back. I can't imagine reincorporating old ways, they are an older me. I cringe at the thought of eating a full pint of ice cream after dinner, which I used to do on a near weekly basis.

Tl;dr: as your body and habits change, so too do your desires and preferences.