When I open my eyes I can see that she is standing right next to me, and she says that the train has arrived in Amsterdam.

The train is completely empty, and she has been kind enough to wake me from my slumber to say it is time to get off.

I had nodded off and fell asleep deeply enough that I had not even noticed the mad rush of busy passengers getting off the train.

Sleeping while sitting up is now possible and quite easy at that. Half meditation and half dreaming, as long as I wake up in time that is.