["It seems every day in traffic i'll let someone out and don't get a wave or anything.", 'Thats the worst when you do something for someone and they dont even appear to care!', 'No doubt, but i always try to do what i would want someone to do for me.']
Same! Two wrongs never make a right.  You are doing the right thing.
Any time i let someone out in front of me in traffic and they don't wave i get angry.