In addition to what Hellion said, Aspies tend to make their own routine, and it's better to inform them at least a few days earlier if you intend to break their routine (doctor appointments, shopping, etc.). Some might not like to touch others and be touched themselves, dislike eye contact and discuss mainly about their topics of interest. There are both silent as well as talkative Aspies. Myself, I communicate with strangers only if they are nice people (I usually sense this).