There are some concepts in life that are just flat out funny. The most common characteristic is that they can be understood by everyone. Without further ado:

Kids Getting Hurt
Little kids getting clobbered is hilarious because their bodies are tiny. It’s like they barely even get hurt because they are so small. Plus they aren’t very bright so they get themselves in situations you could never think of.

Safety Check? Fail.

That vehicle looks safe.

A little more spring.

Farting
It was hard to decide if pooping was as funny as farting but people can get grossed out by turds.  Farting makes a hilarious sound followed by a brief moment of stench. Sharting is also hilarious.

Blast Off

An actual fart

George Carlin on fart jokes.

Unpredictable Pets
It’s not funny if you know it’s coming. When something completely happens out of the blue that you could never anticipate, especially with animals because you have no idea what they are thinking, it’s funny.

One is not enough.