You're Amazing, However
I think you are amazing! Everything about you says I am a Professional and know more than anyone about my field. There is not one person in the office, higher than you or below you, that doesn't say great things about your demeanor, personality an skill set. You're not perfect, but you're so close it's scary. Actually, this whole idea you have about yourself is a bit scary.
I'm all about tooting your own horn and believing in your own greatness. However, I don't believe in staying the same for all of time. Nope, I think as good as you are at what you do it's time to reach out into an area where you will have to not only learn but rely on others to grow into this new skill. Yes, rely on others; I said it. I'm normally the first person to say, know it for yourself by yourself but there is something more than just knowledge to be gained but a trust relationship between yourself and co-workers.
Asking co-workers to teach you something, the same way they all ask you, shows a true leader. Also, shows you can identify the other experts in the department and feel a kinship to them. Sure, there are some people in the department who should never know you don't know, but to ensure you keep those types at bay you must befriend the others who can be trusted. This isn't an article about trust, it's about changing a habit of learning on your own.
This week, choose something you're not very knowledgeable about, find a co-worker who is and ask to set some meeting times to learn it. It will give new life to your career goals, network connections in the company and open up a new relationship which may lead you in a direction you will be surprised to find is good for you.