I know that it is very rude to take a photo of a stranger , but I couldn't help doing it....
I've never slept like him on the train as far as I remember, but it must have been a inevitable nap for him on the train.
I really understand how much he tried to keep himself from not falling asleep like this, and I'm sure that he just lost a fight against sleepiness.
Anyway, I found a nice souvenior in the U.K one day, and it says like
"You know that you are getting older when your happisess is a nap"
Hmm, it is for me now!!!
