Talk:Corvo Attano/@comment-206.231.103.249-20130212002040/@comment-27202257-20130212010226

It's entirely possible that he's been good at it forever, it just wasn't the primary part of his work as a bodyguard, so people were unaware of it. If you're going for a ghost playthrough and eavesdrop on people, they talk about how he vanished without a trace, and sound really surprised about it. If his stealth skills were widely-known, they probably wouldn't have been so shocked.

As for where he learned it--Corvo is somewhere in his 30s when the game starts. We know nothing about him before that, excluding a few moments here and there. He could've learned it at any time.