This nazm written by Gulzar was also used by him (partially) in the very poetic movie Ijaazat. As it happens, one of the protagonist (Maya) is a poetess. And the hero (Mohinder), besotted by her, also keeps reciting her poems frequently (in this scene, for example). How one wishes our day-to-day conversations were as lyrical.
This poem talks about how one keeps on living even when there is nothing worth living for. It is as if we were living out of habit, just for the sake of it. "Aadatein bhi ajeeb hoti hain!"_______________________
साँस लेना भी कैसी आदत है
जिये जाना भी क्या रवायत है
कोई आहट नहीं बदन में कहीं
कोई साया नहीं है आँखों में
पाँव बेहिस हैं, चले जाते हैं
इक सफ़र है जो बहता रहता है
कितने बरसों से कितनी सदियों से
जिये जाते हैं, जिये जाते हैं
आदतें भी अजीब होती हैं
What a strange habit breathing is!
Such a peculiar custom - this thing called life!
Not even the slightest stirring in the body
Or so much as a shadow in the eyes...
Yet the feet keep walking senselessly
A purposeless journey that's been in motion
For many years, many centuries.
(And) we have kept on living (out of habit)
Habits are such strange things!
[रवायत = Ravaayat = Custom
बेहिस = Behis = Unconscious]