It is, however, one of the most famous, noteworthy, and innovative riffs in all of drum history.
I can play it, and do often, and I'm a complete hack. It's not that difficult.. it's the innovation, and adherence to 'what works' compared to what is just bravado.
It is brilliant, even more so.
Again, it is Not hard...it's just so incredibility unique. not that it's 'easy to play'. It took me me a couple hours. For a good drummer probably seconds.
Mostly,however, how did you know that? Very well known among drummers but I seriously doubt even a VERY advanced musician than me like Steve would have known this.. how did you?