lack of physical work with poor or average genetics. just look at the forearms of the people who do hard work. even lifting cannot compensate for that because usually that happens to late. sure you can probably out-grip someone who has much weaker genetics than you do but you will be forever behind in potential. for example these turks who worked in the german mines doing hard work since age 16 or so they all had massive forearms despite often times having thin bodies. 2 generations later their sons are now working white collar or are unemployment they have very underdeveloped arms. it also affects handsize. the old people who worked even if they are much smaller than you will often have equally big hands or even bigger ones. even if they are like 20cm smaller. its because they worked early on. hands are the only place in the body that are like that for some reason. i never found out why.   dude you are an addict, take your own advice and zip it.
Switzerland