Nothing lasts long these days!
As Confucius says, "Hare today, gone tomorrow!"
Alright, listen up, chucklehead. This joke is playing on an old saying, "Here today, gone tomorrow," which means something doesn't last very long. But get this, the joke replaces "here" with "hare," like the animal. It's funny because it's unexpected, and you're probably not smart enough to see it.