I think hyper focus on anything is more likely to be classified as "nerdy" today. People will say "I'm a huge guitar nerd" or "I'm a huge gardening nerd" or whatever.

Related (for the non-grey/whitebeards who saw Revenge of the Nerds): Calling someone a nerd used to be fairly demeaning. Today I would say it swings between okay/acceptable and funny/cool, depending on the social circle.