I have several hobbies but honestly one of the most self-serving is this one.
Photography, I can share my photos with others
Hifi personal audio, I can let them enjoy the aural bliss
Pens, I can write nice letters for special people
EDC, I can always be ready to help those around me
DIY electronics, I can make bang for buck amplifiers for friends
Musical instruments, I can play nice songs for a group, or go jamming
There are a couple of others like watches, coffee and go-karting, but lasers are really quite unique.
Granted, if not for this forum we'd all be staring at dots and beams without sharing ideas and keeping ourselves safe. Personally there's something about the way the beam excites the air around it that mesmerizes me. The danger it poses and the initial fear it instills to the uninitiated adds to the adrenaline but also reminds me to always be aware. The science behind it isn't all that hard and studying about laser circuitry can be quite fun.
De gustibus non est disputandum