Yes, the player is supposed to break into Gehn's lab on crater island, leave the lab through the second door, then take the tram to survey island, where a nice little video clip plays of one of Gehn's scribes spotting you and fleeing. If you pursue him, you'll take the tram to jungle island and land immediately inside…

Venerable Monk, you were not supposed to find that tiny switch from that side! You were meant to take another path that would lead you to the inside of the "wooden whale" totem from the back. Then, if you had opened it from the inside, you would have noticed the tiny switch on the front immediately as a way to get…

It wasn't impossible. Many people solved Riven on their own, I'm one of them.