It's proven that cracking your knuckles will have no effect

yeah but it might make your knuckles swell in the long run. Plus is makes your hands weaker, too.

Yeah, the only way it could cause damage is if you do it A LOT which could cause the tissues to rip.

That's true but what does happen is that the cracking sound is a gas in your knuckles being released and it sorta just leaks out every time you crack your knuckles. And over time it makes your knuckles look bigger because the gas/air isn't going anywhere it just stays near your knuckles. and eventually when the gas is all gone it will hurt to move your knuckles (like arthritis)
don't get me wrong, i've been cracking my knuckles for 4 years and don't plan on stopping lol

I've been trying to tell people this for ages...