We had a player who was reliable for rolling terribly. The kind whom other players were afraid to share dice with, lest they be cursed. So this player makes a Bard, and in the first game, when the party is initially meeting, he wants his introduction to be singing in the town square. We're all expecting his roll to indicate his performance is akin to drunken karaoke.
He rolls a 20... for the least consequential roll the character will ever make. The party was amazed by the golden voice issuing from the brightly dressed gnome.
I don't think he landed a single attack with the character the rest of the game. :P
This is the interesting thing.
STATISTICALLY across a few thousand rolls everyone ends up with an almost identical numbers of ones and twenties as everyone else.
In PRACTICE though some people get those twenties when it makes no practical difference and have their share of the ones show up at the most inopportune time.