Professional footballers are often their own worst enemies when it comes to being yellow carded.
While getting booked for a bad challenge is part and parcel of the game, sometimes players don't help themselves and give the referee no choice.
There's even been some cases of players forgetting the rules of football, as Paris Saint-Germain's Marco Verratti demonstrated earlier this year.
In a game against Nantes, the Italian midfielder literally got on all fours and used his head to nod the ball back to Kevin Trapp, who duly picked it up.
But what Verratti didn't realise is that using trickery to pass to your goalkeeper is forbidden. He was booked as a result, while Nantes were given a free-kick.
Dissent and disrespect is another common - and stupid - way for players to get shown a yellow card, which Arjen Robben was guilty of on Wednesday night.
Borussia Dortmund travelled to face Bayern Munich in the DFB Pokal semi-finals, with Marco Reus giving the away side the lead.
Javi Martinez then equalised for Bayern in the 28th minute, before Robben produced the half's most comical moment.
In the video below, with Dortmund lining up a free-kick, the referee draws his magic line to mark where Bayern's players must stand.
But Robben is having none of it. He's so convinced that the referee has misjudged the 10 yards that he actually starts counting them himself to prove him wrong.
The referee then turns around, marches up to Robben and shows him a yellow card. Check it out.
ROBBEN VS THE REFEREE
Unnecessary, but hilarious. Dortmund's free-kick came to nothing in the end, with Bayern taking the lead through Mats Hummels in the 41st minute.
From Franck Ribery's cross, the former Dortmund centre-back produced a clinical finish to find the bottom-left corner.
Bayern entered the half-time break 2-1 up, though the away side fought back to clinch a 3-2 victory and reach the DFB Pokal final.News Now - Sport News