But I do feel like you are putting words in my mouth: "are you seriously saying that you know everything"
Where the hell did you see myself saying that?
If you read my other replies - I said I have an intense passion for learning. This means I do learn from other people than myself.
You're right... A competent programmer should be able to jump between languages.
I don't think Ruby is the best programming language in the world - but it has suited me well for what I'm doing and allows me to iterate through development cycles quickly with ease, plus there is a large community built around it in San Francisco.
When something better for the job comes along I'll pick it up just as quickly.