大爷待我发及腰时你都老了
[dà yé dài wŏ fā jí yāo shí nĭ dōu lăo le]
It carries an implication of time passing by. The owner may have waited for a very long time and this phrase suggests even if someone waits until the user’s hair grows long enough to reach the waist, that someone would already be aged and gray.