After one of those looooooooong days you really get those feelings of having accomplished something. I do anyway other than those days i take it for granted.
Those acts of kindness though, me too for that. It wears off man. Just like you said when the traffic is thick and you have the ability to give someone a break that you see no one is giving the whole time your approaching. Yep, that's a great feeling.
Almost feel selfish sometimes like I just did it to get the feeling I did something for me instead of for the other driver. LOL