[2] Gilbert was educated at Edinburgh Academy and the University of Edinburgh, though his studies at the latter ended after a year, when he joined the RAF Coastal Command during World War II, flying Handley Page Halifax and Boeing B-17 Flying Fortress aircraft from RAF Wick, Scotland.
[2][3][4] After the war, Gilbert enrolled at the Royal Academy of Dramatic Art, and he initially aspired to direct films.
[2] However, he also acted and wrote for theatre, and it was through this that he began a collaboration with Julian More; their 1956 show Grab Me a Gondola was a success, and led to Gilbert being offered a trainee position at the BBC.
According to the Daily Telegraph obituary of Gilbert, the two men "were largely responsible for establishing the pattern of the show with its quick-fire verbal gags, double entendres and cavalcade of naive caricatures of British life: bumbling colonels, half-witted yokels and bosomy barmaids".
[2][3] In 2003, Gilbert appeared on the documentary special 30 Years of Last of the Summer Wine to discuss his role in helping to create the series.