Metaphorical onanism means doing things for one's own satisfaction without wishing to interact with other people in a meaningful manner, such as learning from them. Trolling is the same, specifically for the enjoyment of making others angry. (From "troll" in the meaning of "mischievous spook" - not referring to physical attributes.) The only difference between trolling in a pub and on an Internet forum is that for the former you may risk a beating. Persons' degree of "reality" is not very different; we know each other only to a certain extent, often less than we think. However, anyone who wishes to build a reputation on her or his real name or nickname has to be careful - Mudcat has a stronger memory than most pub custom, and is more numerous.

Occasionally we read something like "In real life she is quite different" - which means that those who only know her from oral communication do not know her really well either.