My dear Jack, there is something called fevered imagination which afflicts young men. When we have a desire for a woman our imagination can be so fevered we begin to romanticize what does not exist. Your imagination will produce another version of the lady for you. It will be a warm imagery powered by desire. You will begin to see what is not in the real life person, get pleasure from the phantom your imagination creates. If you juxtapose the real life person with the fevered imagery, the real life imagery will feel cold. Can jolt to reality. The fevered edition of the woman produced by your imagination is desirable because you’re projecting your desires. In other words, you’re falling in love with the woman you created in your imagination, not the real life person.