T.I is back in jail again!! Did you not learn the other times?? I guess some people like being put away!!

T.I. has officially begun his 11-month stint in an Arkansas prison. Law enforcement sources told TMZ that the rapper checked in "sometime [yesterday] afternoon."

Tip was sentenced to 11 months behind bars after his drug possession arrest in L.A. back in September. Although he wasn't charged in the L.A. case, his probation -- related to a federal gun conviction in 2009 -- was revoked.