Caveman Mode 

Caveman Mode is the act of doing something so stupid, your brain must have reverted to that of a caveman. This holds the same meaning and use as brain fart does.

Person 1: What were you thinking?!?!
Person 2: My brain went caveman mode

Caveman Mode by extremecheesehead February 2, 2022

Caveman mode 

When you're just too horny and can't really think about what you're doing.

When you're in caveman mode, it's important to ejaculate as soon as possible in order to reach post-nut clarity, or it could lead to dire consequences.

Don't stay in caveman mode too long, we don't want you going to jail for cumming in that girl's coffee.

Caveman mode by Yesmannen July 28, 2019

Modern Caveman 

When there is a huge blizzard outside and there is snow blocking your doors and you can't get out.

"This blizzard is so bad, I feel like a Modern Caveman stuck in my own home."

Modern Caveman by crazyfunnycool February 6, 2010