Some verses get repeated for thirty years. Most do not, including plenty of technically superior ones. The difference is less mysterious than it looks.
It has to be sayable
A quotable line survives being said out loud, badly, by someone with no rhythm, in a conversation. That rules out anything whose effect depends on the beat underneath it. Lines that live in the pocket often die outside it. Lines with their own internal rhythm travel.
It has to be short enough to hold
Most quoted lines are one or two bars. Beyond that, people paraphrase, and a paraphrase is not a quote. This is a hard constraint, and it is why dense multisyllabic runs — impressive as they are — are rarely the part anyone repeats.
It has to be usable
This is the one people miss. A quotable line is one the listener can deploy in their own life. It names a situation they recognise, and it names it more precisely than they could. That is why so many of them are boasts, threats or complaints: those are situations everyone is in.
It usually has one strange word
An unexpected word choice in an otherwise plain line makes the whole thing stick. It gives the memory something to catch on. Fill a bar with strange words and the effect disappears — you need the contrast.
None of this is a formula for a good verse. Plenty of great writing is not quotable at all, and chasing quotability is how you end up with punchlines stapled to nothing. But if you are wondering why the line you were proudest of is not the one people repeat back, it is probably failing one of the four.
