Intense kids can be physically and mentally exhausting. I have to force myself to take time for myself now and then, and when I do, I find I am a far more patient and calm parent. I don't worry about my brain turning to mush, as I exercise it regularly with books and writing, as well as discussions with gifted friends. But I do suffer from burnout now and then, and it is hard on the whole family when I get to that point.
I encourage all parents to build some "me" time into each day, if only for a cup of tea, a bubble bath, or a half hour with a good book and no interruptions.