Where is the C Key on a Piano?

In Western music we use 7 letters of the alphabet A B C D E F G and then back to A. Therefore the C key is the one to the left of the D key. This is important because it is easy to remember where the D key is on a piano, as follows:

If you notice above there is a group of two black notes and a group of three black notes.
If we can imagine the big set of three black notes is Grandma's house and the smaller set of two black notes is the dog house.

Inside the dog house is the dog and "D" is for dog. Inside Grandma's house is Grandma's famous apple pies just freshly baked. We have then "G" for Grandma and "A" for apple pies.

When we now look at a keyboard the keyboard notes D, G and A should be easy to find.

All the other letters can be worked out from these by going up and down the alphabet accordingly.