When the Switch was announced, I had lots of faith in it. The concept felt very appealing to me - but as a fan, it is not that hard to convince me to be honest.
One thing was remarkable back then, I heard people (ex gamers or rather non gamers) talk saying things like "that new Nintendo (console), it lets you continue a TV play session on handheld on the fly anytime, this makes me want to play (again) " or "I won't be bound to our TV for gaming, that's great". Basically, people in their early thirties to forties seemed to be quite attracted, what I could observe. The nearly seamless transition from a "big" game like Skyrim from the big screen to a portable on the same device with basically the same fidelity was something new.
As I said, I thought this would be quite a success. But THIS surpasses my expectations, even my optimistic estimates were nowhere near the DS or the one in a lifetime success of the PS2. Yet here they are, setting a new milestone in Japan and maybe worldwide before it will be discontinued - and it hasn't even seen a price cut to dirt cheap like in the PS2's late life cycle by now. Astounding.