This does not mean that you must donate all your worldly goods and live the rest of your days in poverty. What it means is that, when the time comes to vote in a property tax increase to fund education, or public transit, or any of a host of things that you think don't affect you personally, you have a responsibility to consider how these decisions will affect people who are not you, and that you should at least try to decide in favor of those people, if at all possible. I'm asking you to consider providing some resources as part of your duty to the rest of society, so that those less fortunate can have some hope of bettering themselves just as you did.
If we have any hope at all of maintaining an orderly society, we have to stop thinking only of ourselves.