Well... Since you can NOT get the flu from the shot that means you already had the flu by the time you got the shot. Getting the flu is no fun to begin with. Getting the flu shot when it first comes available does prevent this. I have had the flu one time in my life. It just happened to be the one time I did not get the shot. I have been ill before but the with the flu I felt my life was near the end for a couple of weeks. The flu shot is far less painful.