Along the way Doc encounters a slave girl who sees him throw down some patented Sorcerer Supreme mojo. She reaches the logical conclusion.
Doctor Strange, being a smooth operator, plays down his magical badassitude.
The line "These forces are within us all!" made an impression on me as a youth. Magic surrounds us, penetrates us, and binds the galaxy together. It is available to all. This simple concept haunts me to this day. Magic-users may need special educations and expensive/rare material requirements for their enchantments, but they are not the elect. They're closer to Batman than the X-Men in this regard. Anyone with sufficient desire and dedication can make magic happen; there's no special gift the lack of which prevents someone from joining the fellowship of the arcane. A wizard isn't automatically a Chosen One.
Credit: I couldn't find my copy of Doctor Strange #53 yesterday, so I swiped all the images above from Bully's treatment of this issue. My buddy Pat made sure I saw yesterday's awesome Bully post and you should check it out too.