If you keep your carbs low you can eventually adapt to it and feel energetic and alert like normal again. At the other end you can eat more carbs and feel energetic and alert so long as you don't go too low carb for too long. But then there's that gray area where you can't seem to adapt to lower carbs and you feel tired or weak.

How is it there is this gray area where it's difficult to adapt, where you just bounce around miserably forever, never adapting, never improving? Can you ever get over that and adapt to the gray area?