Glib or lighthearted recognition of some mistake one has made, regardless of how serious (or not) the mistake may be. Sometimes said more colloquially as "sorry 'bout that." A: "Oops, sorry about that. I didn't realize you were still using this computer." B: "Oh, don't worry about it. I'll just log in on a different one." A: "You ruined my entire batch of brownies!" B: "Oh yeah, sorry 'bout that. I needed the oven, though, so I just took them out."