Yeah I don't really need anything for my birthday (and so by that logic also Christmas). But if you did want to dump some money on me, you can give some money to help some people.

You won't ever know the extent of your help
You won't ever know the people you helped

But you will know that you have given.
And as the cliché goes it is better to give than to receive, but like most old proverbs there is truth in them.

Any amount you give will do, as long as you are not hesitant. Don't see this as a task. But see it as a chance to change someone's life.