Yes i totally agree with you! When i go low or hypo, i can still function. I get hypo signs and feel a bit rubbish but i can carry on with my job. It's been 5 years since my last fit/hypo coma thing which my boyfriend helped me with. As for training the brain, i haven't done it with being low but it definitely happens when you're consistently high for a while! I was ill over christmas and had high blood sugars for about 2 weeks, when they came down to normal i was getting hypo symptoms at 6.3. I think your brain gets used to the high (or low sugar) environment. However, personally i feel like constant low sugar is a lot more dangerous, as the brain isn't getting enough fuel.