i accidentaly erase myself from all groups, I wander what are default groups that user belongs to?

http://wiki.linuxquestions.org/wiki/...o_belong_to.3F
Now I see the section is Ubuntu...Still, probably it's useful

thank you...

Another way around would be to create a new user and check out the groups s/he belongs to. Though I have the impression that by default Ubuntu adds the first created user (during the setup) into more groups than regular users, and gives this user ("main user after root") more privileges than any other regular user created after that.

Still, nobody should belong to any group they really don't need - start off following the rule of minimum privileges: only add the basic groups (perhaps looking at some newly created user), remove those you think you don't need and add new groups only if something "doesn't work" without it. It's no use to belong to the root group if you don't explicitly need the permissions -- basically in that kind of a situation you're just creating a security risk, if you're giving yourself more privileges than you need.