In addition to learning verbal language, human beings are expected to learn and adhere to a series of complex (and often pointless or contradictory) "social norms" that determine how we interact with others. But learning these rules and patterns is much easier for some people than others. Autism spectrum disorder (aka ASD) impacts a person's nervous system, and one way it can manifest is in difficulties interpreting the social cues and norms that others take for granted.
1.) From mother-of-monsters:
I found out that holding extended eye contact is pretty much universally unappreciated. I always thought that giving full attention was respectful, but recently was told it comes off as the opposite. I’ve had to practice looking away at appropriate times. It’s frustrating because I watch people for hyper-detailed body language, but conversations go better when I look away briefly for their comfort.