Every now and then I have an insight that is so simple that it is almost obvious; and yet, it seems to be the truth.
The Mishna in Avos teaches that a wealthy person is one who is happy with his/her lot. Meaning, it is not how much you have, it is how you feel about what you have.
A wealthy person is someone who lacks for nothing. So if you are happy with what you have – then you lack nothing. Thus if you are happy with what you have – you are a wealthy person.