Also, how does one average their level of knowledge against things they don't know? If you asked me how good I was at C# 3 years ago, I probably would have said

Also, how does one average their level of knowledge against things they don't know? If you asked me how good I was at C# 3 years ago, I probably would have said 75%. Three years later, I would say 65%. I'm significantly better at C# now than I was 3 years ago, but I'm also more aware of the things I don't understand. I also recently saw a Jon Skeet talk and it ruined my level of self-worth.