Q: Why can’t you play hide and seek with mountains?
A: Because they are always peaking!

Explanation: Hide and seek is a game that children play.  In this game, one or more child finds a place to hide while another child closes his or her eyes and counts to 10.  When the person counting gets to 10, that person goes to look for the ones who are hiding The person who is counting has to close his or her eyes in order not to see where the people are going to hide.

If the person who is counting secretly looks to see where the others are hiding, that is called peeking.  To peek means to take a small, secret look.  Peeking is not allowed while playing hide and seek.

Peek (to secretly look) sounds just like peak (the top of a mountain).  When you get to the top of a mountain you get to the peak.  (If you like grammar, peek and peak are homophones.)

This joke is funny because it plays with the word peek/peak that sound the same but have very different meanings.  Clearly, mountains cannot peek, but they have a peak.

Here is some motivation from Sister Sledge for you to reach your peak: