No worries mate.
I think it is human nature to disbelieve someone can surpass you with half the effort.
But some people have exceptional brain genetics without "trying", for example, and no one really questions that.
Some of my mates locally are proper scarily fucking massive guys - mostly West Indian to be fair to them - but they are huge - 17-18 stone without ever going to a gym, then 20 stone of off-season shape, maybe more, with a bit of gym effort as an aside to their boxing training.
We're not all equal - I sometimes see guys in shorts wandering around Tesco with zero definition, zero delts or arms - you can tell they've never been in a gym in their lives - but their quads, hams and calves, etc are plain fucking stupid massive from a bit of rugby followed by 10 pints after a game.
That's genetics.
Lee, IMO, got those genetics in nearly every body part.
Luck of the draw.