What would you do without me?

Today was a blah day! I was thinking of what the purpose in my life is and of the things I have done and the things I am doing now. I was wondering.... have I made a difference. I am realistic and know that at this time in my life a difference I am looking for is not one that would change the whole world but maybe change someone... or help someone that I care of. I wonder if I have done this already... have I really changed someone... have I made a difference... and if I have... What is it? Is there anyone that would be thinking in a future about the positive effects I have brought? I don't know... this has been going through my mind today.