Really....no, really?

Do you ever find yourself driving and oh, there's someone that wants to merge into traffic; so, as any normal/kind person would do, you slow down to allow them to merge, turn or whatever, and then it happens, or doesn't happen. That's right, I let her in front of me and she turns and drives on WITHOUT a thank you wave. Huh? Not even a slight nod of appreciation? I'm sorry, did you think I waited here all day to let you in front of me because it is my job? I'm sure it would never cross my mind to speed up and on Top of said people...that would just be atrocious of me. I have to say though that it annoys me even more when you hold the door open for people and they just walk right past you, especially if it is a man. Really...no, really?