Not a good idea: taking the 06:40 train on Sunday from Amsterdam to Haarlem and then falling asleep and waking up just as you're approaching Heemstede-Aerdenhout. Because the next train back (a 5-minute trip) will be 45 minutes later and at that time in the morning, in a place you don't know with no stores in sight open there's not really anything to do. Besides slamming your head into the wall for half an hour because the falling asleep part was stupid.