It was a pity that in their trailers for the show, Channel 4 said that GM was the first amateur to try to get a place on a F1 pit team.
He's a fully trained and time served HGV mechanic, so hardly a novice at that sort of stuff.
The show was mostly about his becoming quick enough at putting his tyre onto one corner of an F1 car though. There really wasn't a lot of HGV experience required, just the ability to lift a tyre onto a big wheel nut without taking more than about 0.5 seconds about it.
He was, as he always is, full of enthusiasm. He's a person who gets all the joy he needs from life as long as he has a cup of tea, some spanners, and something mechanical to fettle.