examples: doctor had 3 or 4 surgeries.. he wants to crash, but here is an emergency..
soldier just had a late night crash, but he is woken up that enemy is near and they have to be on the go.. and he slept only 2 hours..
what is the secret that these people have to be able to endure.. just coffee or more than that? it is unthinkable and we never hear of soldier dozing off due to tiredness or doctor dozing off during surgery etc.
~I can understand this if the job is to play computer games 18 hours a day :)
then maybe one will never be tired!!??