It's wonderful you had a moderation regarding what "friendship" meant to you personally. Fortunately, you did not let the judgmentalism of the Watchtower impact you. Most JW parents run a tight ship on association for their children. Many JW kids like to associate with non-JW kids at school. Extracurriculars, school or otherwise were forbidden by most JW parents with regular admonitions. Most JW kids find a personal contradiction wanting to have non-JW friends, but however, being taught and believing somewhat, that their God, Jehovah, was going to destroy all non-JWs soon. (oh, the pain of heart I had going door to door calling on a fellow students and even teachers - didn't know where they lived)
How much a JW youth absorbs, takes to heart, lives with personal conflict, is complex, impacts each one differently. I saw very frequently, when one parent, often the father not 'in' at all, or not as devoted to JWism, leaves a window open for many children to be more independent of thinking and a very high rate of those leave the organization very young and not with much trauma.
However, when both parents are very devout, father is an elder or ms, mother pioneer frequently, often, there is no or not much room for independent thinking on the part of the JW child. For this child, as one grows and matures, on into adulthood, there is much re-education, re-analyzation to go through, it can take time and a lot of effort.
Certainly, it is worth it and when raising our children, we find much joy raising them with freedom of heart and mind.
