Rocky is bad!!

I take a barrier and put it over the stairs...Rocky beats it up! Rocky can now remove the barrier and he stands at the end of the stairs as if he's a champion. What is wrong with him. I know he stairs are dangerous so I run to get him but since I was told he can fall down and crush himself, I couldnt imagine. All I thought about was a stair or two but I guess I could understand the tumble.
The way rocky jumps off furniture, he will duck and dive no? I surely dont want to find out!

 

[xp29]

They can be pretty clumsy, stairs could be really dangerous. Maybe a doggy gate?