When I was on a keto phase, one day I noticed that I was so clear headed and energetic that I thought something broke inside me. It was like a persistent coffee kick without the side-effects. I realized that the feeling was probably how "normal" should feel. It changed my views about a lot of things. I would walk down the road and realize how many business fronts were restaurants, of which I had no desire to enter. I never bothered with any checks for keto, I just ate loads of low carb veggies, a little bit of meat, and coconut oil for added fat. A note on the oil, I had to make sure that I took it with meat, or else I would get sick to my stomach.
My lifestyle changed once I got a live-in partner. I need to get back on it.