You have no way of knowing how or when all the things you do will come back to you. What you can know is that they will.
Some obscure and seemingly useless fact you learn today could end up playing a major role in your life next week, or five years from now. Some small favor that you do tomorrow may come back to you in a few months as a grand opportunity.
Your words do not end when you speak them, and your actions do not stop when you've completed them. They go out into life and begin connecting you with the people, circumstances and things that resonate with those words and actions of yours.
Live as though the things you do, in one way or another, will come back to you. For you can be certain that they will. Namaste.