I spent over 10 years working as a generalist in IT. I have really specialized in SQL Server and SQL Server BI over the last few years. This year I made a point of becoming more active in communities.
I spend at least a few minutes here on SSC every day. The same is true of BIDN.
I am a member of many SQL Server or BI LinkedIn groups.
I have worked to post forum answers in SSC and elsewhere.
I have attended several SQLLunches and a SQL Saturday event.
I am considering writing a few blogs and short articles based on what I have learned.
In short, I believe involvement will make you better. I believe there was another editorial recently that said something like I get better/smarter when I talk to you. I would expand on that and say that being involved in online and in these communities and groups has absolutely made me better at what I do in many tangible and intangible ways. It takes real effort and time, but it will pay big dividends for a long time.
If you want to reach the next level, community involvement is a great way to do it.