Hi Nona , Whatever you do frequently and find yourself liking it and benefiting from , could turn into an obsession or more of an addiction ,some are good and some could be harming ,like excessive use of computer games , if you are addicted to sports that would be beneficial for example .

Surfing, football etc or computer games. For some it is shopping.

Computer can be a hobby that turns into obsession, once you learn it, it captures you

my hobby is learning korean language but now it is an obsession

Internet .