It depends how long the shoe(making?) apprenticeship was, and how old he was when he started it, as to whether Robert is old enough to be a Journeyman.
For example lets say he started his apprenticeship at age 11 and the apprenticeship was for 6 years, then he would have finished it when he was 17 years old, so it is possible that he is old enough to be a journeyman if his age is accurately recorded as 20 years old. If he started a seven year apprenticeship at age 14 and completed it at age 21 it is still possible Robert was a journeyman if he was aged 24 at census time but his age was rounded down to 20.
(added: ages and time frames are just to serve as an example and may not be accurate)

It may also be that Robert
said he was not a Journeyman but perhaps he was big noting himself.
