The perk "Keymaster" (Pickpocket) states "Pickpocketing keys almost always works."
What does this mean? Does it mean that all keys will always have a 90% chance (the cap) to be pickpocketed?
If so, are there keys later on that are really hard to pickpocket? Because where I am currently (not very far) all keys I've come across already have a 90% chance to be stolen, so I'm wondering if this perk is worth it.