It seems to be a thing in (some) men.
They get hold of one particular hobby, and they get fixated on it. Whether it's running, footie, golf, fishing, cars, bikes, computers yada yada. They get fixated on it, and in some cases spend shitloads of the family money on it, and think it's ok to fuck off and leave the wife with the kids while he gallivants off to his hobby/obsession.
DH is luckily not like this, but his mate 'Dan' is. (He is seperated from the woman he was with for 10 years and has 14 y.o. son.)
He is in a running group (coincidentally,) and all he does is go on and on about it. Every. Fucking. Day.
He has facebook, and out of the 150 or so pics he has posted on there in the past 2 and a half to 3 years; every last fucking one is of him running, him training, him exercising, his running group running, his running group posing. Blah blah blah. Even his SON has said 'dad, your pics are great, but it would be nice to see one that isn't related to your running hobby.' (YEP, he hasn't even put one up on facebook of his son - since 2014! Even then, there is only 3 on there!)
He is, by a country mile, definitely the dullest, most boring person I have ever had the misfortune to meet. 
Several other people who are obsessed with something - often a sport! (all men sorry!) are very similar. Dull and boring and consumed with their hobby/sport.
You have my deepest sympathy OP!