[fatfingerd]

I don't think they investigated their survey questions correctly and missed the obvious. I'm not among the 25% who reliably wake up without an alarm, at times I was very far from it being horribly late at least once a week, yet I know from past situations that I can will myself to awake at any particular time, occasionally waking up an hour early (particularly if there is a high stress reason) but more often within 10 minutes of the goal. But there must be a reasonable motivation that I haven't killed by doing it every day for a routine I don't really enjoy.