The dog is also sleeping on the side of a street without any difficulty and the king is sleeping on the palace, very nice apartment. A Krishna conscious person, he’s also sleeping. But there are different grades. The Krishna conscious person while sleeping, is chanting Hare Krishna. This can be done. If you practice this Hare Krishna, even in sleeping you’ll chant Hare Krishna. Everything depends on practice.
Lecture on Srimad-Bhagavatam 5.5.2 — Boston, April 28, 1969