Cuts all over, dozens of stitches, yet amazingly no permanent injuries. She had to spend a couple of months in inpatient care to stabilize.
However, it's still incredibly important to understand whether or not you have these behavioral changes because they can often have a negative impact on your life if you don't understand them and develop coping skills for them. Your behavioral controls might be calibrated to who you are day to day rather than who you are when you're hypomanic. And that can lead to a lot of problems, spending too much money, taking irrational risks, etc. Being able to step back and realize that your feelings and impressions are being filtered by basically a mood altering state (just as you'd realize that you act differently when drunk and need to compensate for that) will help you navigate those behaviors better and be able to retain your ability to act rationally and in your own future best interests.
And, as you note, periods of hypomania aren't long-term sustainable. Ultimately you need to learn how to cope with all of your moods and states.