There was a cliff near my home that about 40 feet high and 1/2 mile long.
When I was about 13 or 14 years old, an older friend asked me to go scrambling up the cliff with him. In retrospect it was probably class 4.
We turned it into a game. We climbed up the cliff, walked 30 feet long the top and then down-climbed, walked 30 feet along the base and climbed back up. Up and down, up and down.
Eventually we started looking to steeper and higher cliffs and bought a rope.