I’ve never really done it before. Nodded off on the train. But I’ve done it twice in the last three days.
It starts with a heaviness in the eyes and around the head. Then a loosening of the neck muscles. And before you know it, your head is up against the window. But the safety glass is no pillow. And it’s not too long before your head lolls forwards, dangling like an undignified gooseberry. You jolt awake as the train trundles through Ely (for example), and try and wedge your head between the seat and the window, anything to gain some kind of purchase. But it’s no good, and soon enough you’re drooling down your own chest. You wipe your chin, look around to see if anyone noticed, but no-one cares.
Overall, I neither recommend nor don’t recommend falling asleep on the train. For a similar experience, try falling asleep on the sofa whilst your loved one pulls it around your home.