Pfaffs

Example:He can be a little pedant about handshakes, always making sure they are firm and direct.

Definition:A person who is overly concerned with laying down the rules of what is correct or proper, often in a tedious or unreasonable way.

Example:He's a real nerd who only talks about advanced calculus theories.

Definition:A person who is extremely enthusiastic about a particular interest or hobby but lacks social skills and interest in other activities, especially when used contemptuously.