How is an tank of gas similar to knowing how to swim?

My good friend just told me that he doesn't know how to swim. I told him:

You should learn how to swim when you don't need to know...

...than to not know when you need to know.

It's like always letting your car's tank go down empty before you go refill it.

It's better to take the time to refill your tank when it's half empty...

...than to have to refill it when you don't have the time.

This mentality should be applied to everything (procrastinate wisely).

Much love and good luck,

M