I absolutely love that, after all these years, Myst is still capturing our attention. I am not a huge gamer, but of all the games I have played, Myst still remains my favorite.
I think it's the first game that really transcended what games were at the time. Prior to PCs, games were mostly just hand-eye coordination checks. Myst was the first game I played that really engaged the brain and problem solving.
There were lots of adventure games on PCs before Myst, where Myst differed was in atmosphere and immersion: it was arguably the first game where you really felt like you were in a different world, as opposed to playing something on your computer. I think that's why it is lodged so deep in collective memory.