後生 こうせい一生 いっしょうじゃないです
kōsei isshōjanaidesu

Noun
Desu Copula
Negation Auxiliary

The polite negative form of 後生一生

1. It's not like I have all the time in the world.; I don't have forever.; I'm not endlessly young.

Negative
Polite
Casual Register