If I influence just one person...

I have heard people say before that if they are able to reach just one person or witness to one person out of all these people or if I am able to influence just one person out of all of this, it will be worth it and I used to think in response to that, "Really, just ONE person? Out of ALL of these people and out of all you've done, you would be happy just reaching one?" I never understood that until now. After having some people ask me questions about how to diet or exercise or tell me how much they believe I can do this OR better yet, if I have just one person tell me how they have started exercising, I truly feel that if I have reached ONE person, it's all been worth it! God is seeing me through this and he lifts me up when I am down. He uses the people around me to get through the ups and the downs. If he can use ME also to witness, influence or reach someone, to God be the glory!