Every person has multiple social networks that they interact with on a daily basis. I think you're confusing your personal friend network with your larger professionally relevant network. All you need to get a job lead from someone in your professional network is for them to have a positive impression of you, even from years or decades ago. That impression can be built up from years of working closely together on projects including building up a close friendship, or from talking to someone for 15 minutes if you really stand out positively to them. Don't undersell the value of the connections that you have. Most people would rather hire someone that the know than someone randomly selected from a stack of resumes.