A previous question asked whether the map of the USA needs four colors.
Now, what about Canada? If you want to assign a colour to each province and territory, so that no two neighbours have the same colour, do you need four different colours?
When I was a young man, I knew the answer to that question. But then, when I was half as old as I am now, I found I did not know the answer anymore!
How old am I? At what point did I get confused?