I know it can learn it at Level 1, but if Pokemon can't relearn Moves in Gen 1, how can it legitimately know it? I'm asking because I was wanting to make an Amnesia Snorlax in the Virtual Console Blue, but is that even possible?
Yes, it's possible. Snorlax can be caught at Routes 12 and 16 in Kanto at Level 30. At Level 30, it'll know the moves Rest, Headbutt, and Amnesia.
Snorlax Gen I Levelup moveset
Kanto Route 12
Kanto Route 16