Taking baths is my damnation. I never realize how much time I spend like that. It's exactly the kind of thing I do while repeating to myself "other 5 minutes...". But five minutes are never average and normal five minutes, they resemble more to two hours...
Same goes for sleeping. I could never stop. Some days I have to ask help to my personal sense of guilt to be able to get out of bed (can be a sofa or an armchair or the bathtub etc...).
Computer laziness, which mainly random but absolutely useless activities, is another dangerous occupation I can waste my time on without knowing when it's time to turn the evil machine off.
Better not even try to talk about shopping... or drinking! Sigh!
Then we have the healthier occupations: music, writing, webdesigning (not included in the computer laziness part of the post because this has actually a reason to be), reading, watching movies or cartoons, gaming. Are they healthier for real or not? Don't know, they look less dangerous for my nerves, but they can become life-threatening considering I just can't stop till I'm nauseated or exhausted