St. Gall followed St. Columbanus into western Europe to found abbeys and preach the Gospel -- part of the way the Irish saved civilization. But he got sick somewhere in Switzerland and fell behind. Columbanus accused him of malingering and ordered a penance: Gaaech (Gall) could never say Mass again while Columbanus was alive. I know it is a sacred ritual and a great honor, but doesn't it seem like punishing a malingerer by ordering him to do less work? Sort of like suspending a kid who skips school.
Gaaech had a couple of cool miracles to his name. Once when he and the brothers were camped in the woods, he ordered a passing bear to bring firewood. The bear complied. He also exorcised King Sigebert's wife -- the demons left in the form of blackbirds. For this, he was twice offered bishoprics, but knowing his limitations (or at least his vocation), he declined.