Jackson's an Olympian! LOL... No, really, he's a natural. Everything comes easily to him, as far as activity goes.
I always encouraged his athleticism, which I know helped, but at the same time, it DID come natural. For example, as a pup, he used to play in the water on the pool cover, and in the pond, etc, so once the pool was opened, I encouraged him to get in. Had I not, he probably never would've gone further than laying on the step. Now, he does this:
So far, he's excelled at anything I've thrown at him though.
He's just very swift, very fast, very agile, quick in his movement. Jumping on/off furniture is very easy for him, he enjoys jumping onto fallen down tree trunks outside, onto benches, picnic tables etc. It's something I don't pay attention to, but he's given others heart attacks!
His nickname is 'Action Jackson' for a reason!