Sometimes (as an intelligent species, and therefore creative, speculative about reality and so on...) we want to experience some situations which aren't possible at all. Then as a writer you can create a character who "lives that cool stuff which I (the writer) WANTED but isn't possible." Well, this thought defines the notion of "A character who was born to fulfill an author's power fantasy [1]." But, again, as a writer you introduce a story. Then you have a character who has this "feature of a Canon Sue" but isn't.
Considering a part of this video [1], how can I identify a Canon Sue? I mean, suppose that you want to fly by yourself. Are you really creating a Canon Sue by inventing a character who can "live your dream"/"do something that the author wants to do but is impossible in our reality" (fly by yourself), even though you have a proper story of this character to tell?
[1] https://www.youtube.com/watch?v=KcXVGIi1m28 (in time interval of 3:16 - 3:20)