Pickpocketing (Risen 3: Titan Lords)

Tell me I don’t understand .... in the game pickpocketing from me at 40 ... I go to the NPC is written in the dialogue to steal 40 60 ... ie. I have a skill of 40, but I need 60 .... but at the same time I click on the line to steal and steal ??? Is it a BUG or am I not completely robbing my pockets or something I misunderstood with theft from pockets, how does it work ???