arrogant (ˈærəɡənt)

— adj

having or showing an exaggerated opinion of one’s own importance, merit, ability, etc; conceited; overbearingly proud: an arrogant teacher ; an arrogant assumption – Source

Also assuming that doing the job provides it all: knowledge, experience etc., without having to read, learn and stay up to date with technology, ideas and trends. Comparing humans with wine bottles, the more you leave them ‘untouched’, the better they get.