Personally, my first step is reflection - am I as smart as I think I am regarding programming/history/science/etc?
Second is to seek out experts. This is much easier now thanks to sites like HN, StackExchange, et al. They can help you gauge your own knowledge level.
Second is to seek out experts. This is much easier now thanks to sites like HN, StackExchange, et al. They can help you gauge your own knowledge level.