Singer Bobby Brown showed up right on time in a Los Angeles courtroom today, March 20, to begin serving a 55-day sentence for DUI.

He was sentenced last month after pleading no contest to an October 2012 DUI arrest -- his third since 1996 and his second last year alone. (He was also arrested for drunk driving in March 2012, and even did a stint in rehab last summer. But clearly it didn't take.)

After he's released -- which could happen as soon as nine days from now, thanks to time off his sentence for good behavior and California's infamous jail overcrowding problem -- he'll be on probation for four years and will have to take part in an 18-month alcohol education program.

At least he's not denying he has a problem. Unlike some people we know.