Two comments on interactions with people:

1. Some people have never learned how to respond appropriately.

For example:
A: I am doing all these really exciting things in my life.
B: I am doing all these really exciting things in my life too.

2. I am the worst person at saying "hello" to people I know ever.

For example:
A: Hey (and a wave)
B: Uhhh (sort of half wave)