For me it was my older brother (who owned the only computer in the house). He had very strict rules about what I could do on his PC but even then he would only leave his room unlocked once a week at most. This was before I even cared for internet so being offline was no big deal.

When I was 13 I managed to talk my way into doing some chores for a neighborhood PC school in exchange for access to computers whenever there was some free spot in any of their classes. A couple years later they opened a Lan House so I worked there and could finally use PCs all day every day. One more year and I was already teaching programming classes there (well, trying to).