When one feels overwhelmed and demotivated by looking at someone else's knowledge or skills, it is a great strategy to put things in a perspective. This strategy is based on reality of individual limitations and capabilities.
The sphere of knowledge in the world is vast. One may say infinite, but that may not be true. There are innumerable branches of knowledge, sub branches of those branches, and almost fractal like nature of further subdivisions of all those sub branches. One realizes this nature of knowledge when one goes deep in any particular type of knowledge.
Let us take music. At the top level there would be a geographical divide of music. Divide between classical and popular. Divide between jazz, rock, rap and electronic music. Indian classical vs western classical. Hindustani vs Karnatic. Scales vs modes. It is never-ending. Once you get deeper in any of those branches, you would realize they have more complexities. Every instrument has its own nuances. Every playing style can be further enhanced. You can augment guitar solos by playing drum like sounds on the guitar body. It is never-ending.
This is just one of the human endeavors called music. What about science? Physics, chemistry, biology and further subdivisions? Different theories of fundamental forces? Nanotechnology anyone?
The only reality is that any individual can be defined only by infinite ignorance. However much you know, you will not know vastly more things. When you look at anyone you think as a daunting intellectual in any field, look at what he or she does not know. Suddenly, the person would not look so daunting. All of us are related by our infinite ignorance of things, or if you prefer, vast ignorance of things. It is the vast sea of ignorance, that is the fundamental reality.
Once you realize this truth, the comparisons can stop. You are just like anyone else, and any effort to gain any knowledge is purely your own. Any effort would lead you to knowing more, just from your own perspective. You are your only benchmark. You may be navigating the knowledge path of the experts, but where you are and where you reach is your own daily struggle. The best way to gain knowledge or skills would be to have a very personal connection to the path. You can look at the experts, or people who are better than you in a particular domain, but not to compare. You can look at them as one of the sources that you use to emulate, to learn. And since you are unique in your own endeavour, probably you can teach them something too. Not what they already know, but something they do not know. Someone rightly said, "The only way to beat Bobby Fisher is to play something other than chess."
It may be ultimately real that you will be compared with other people, especially when you want to use your skills to help someone, or to entertain someone. Consumers of your services would want to make sure they would get the value for the money they are paying, but that is still away when you are starting the path of learning. When you want to make sure you are not overwhelmed with the multiple voices, the immense expertise, the nuanced skills, you need to just focus on your own journey. The thought of potentially selling those services can wait.