We've all brought extra clubs to the course at one time or another without regard in a friendly round.
But when you do it in a competitive round, it sure can hurt your score in a heartbeat.
So when Woody Austin began his second round of the PGA Championship at Oak Hill on Friday, nothing was askew. But Austin failed to keep a bulky out of his bag that already was at the maximum of 14 clubs. That's a big no-no when it comes to the United States Golf Association's rulebook.
And thus Austin was assessed a two-shot penalty for each hole that the extra club remained in his bag.
The total damage after it was discovered on the third hole was four shots - the maximum for the rule breach.
Austin shared in the responsibility for the miscue, which wasn't noticed until the third hole due to a rain cover blanketing the clubs to keep them dry from Mother Nature.
Austin posted a 75, which left him at 4-over par for the championship after his opening 1-under par 69.
He missed the cut as a result, and would have made the weekend if not for the four-shot penalty.
It's not the first time the mistake has happened in major championship golf. The last time, and probably the most famous outburst in golf, came from Ian Woosnam in the 2001 British Open.
Here's a clip from the mistake that cost Woosnam some momentum and a chance at the Claret Jug:
Hopefully, Austin's caddy doesn't meet the same fate as Woosnam's did following that fateful final round in '01. (Hint: he was fired).