I did keto properly once back in 2011 or so, lost 15kg in 4 months and kept it off for a year at least. Then tried to jump back on several times without success.
Biochemically, keto makes perfect sense to me, and I'm a biochemist by training. It also pairs very well with intermittent fasting (basically missing breakfast, which for me is second nature - I never get hungry before midday), add some weight lifting on top of that and the fat loss is surreal, combined with never feeling hungry, having mental clarity and tons of energy. On the same thread about biochemistry, the typical high carb low fat over 6 "meals" per day dieting advice is bonkers, basically makes me hungry, angry and miserable and I don't lose a gram.
How to get back on the wagon though? I remember when I did keto I used to look at people (like me) eating all the high carb stuff and felt going and telling them there's a way to get back control.