I'm 50, and I've voted in every election since I turned 18. At no time in my life, or probably my parents' voting lives, has voting made a positive change to the big picture.
We don't select who we send to Washington. We don't even get to choose who is on the ballot. We only get to pick between those who have been chosen for us, and trying to effect change is an exercise in frustration, from the precinct level on up.