dear stressed--dissociation happens in different places and under different circumstances for everyone. when i'm going through a really rough time, i can dissociate everywhere. the funny thing is that most people aren't even aware that i'm dissociated. some people seem to snap out of it rapidly, and others can dissociate for differing lengths of time. there have been times when i've dissociated for hours. sometimes i'm alone (really bad when driving, as someone noted), sometimes with my therapist, sometimes with friends, sometimes in public places where i know no one. there are techniques that can help if we are aware that we are in a situation where we are likely to dissociate. the importance is remaining grounded. the key, i think, is to use as many of our senses as possible.

as to your other questions: i usually do not have a sense of lost time, so i am sometimes brought up short by looking at a clock and seeing that time has passed or noticing that the sun has set. sometimes, i am sitting in the same place; other times, i have gotten from point a to point b and don't know how i did it. other times, i have written or drawn something while i was dissociating and when i "came to" did not remember doing it.