The Talos Principle

When you are stuck on the same puzzle for a long time Elohim will suggest that you come back to the puzzle later. Once the line completes simply exit that puzzle area and the achievement will pop. It doesn't work the first time he mentions it in the early tutorial puzzle since this is scripted when you walk into the puzzle.

This is missable because he may only say the dialog a few times in a playthrough, and it's unclear what the actual conditions are that trigger it. For me it didn't happen until I was doing World C with around 35 red sigils. I also spent a significiantly long time in that one puzzle, so it's possible it could happen far sooner if you mess around in a puzzle for a bit.