just because

"Because" is often shortened colloquially as "'cause" or "cuz."

1. Used to introduce something that one does not believe serves on its own as an appropriate justification for something else. What on earth were you thinking? That it was OK for you to break the law just 'cause your friends were doing it? Look, just because I run the company, it doesn't mean that I don't understand how my employees feel.

2. informal For no specific or meaningful reason. A: "Timmy! Why did you draw on the walls?" B: "I dunno. Just cuz, I guess." A: "But what they did wasn't illegal at all." B: "So, what, they went through all that effort to keep the whole thing a secret… just because? I don't understand why they would do that if it didn't serve some purpose."