As human beings, we often want to find meaning in things around us. Why does the apple fall straight? Why is the sky so blue? Why is purple not really a color? While these questions are certainly a great way to understand your world, there is another world you are neglecting: your emotions and feelings.
Lots of photographers out there love the idea of getting a candid portrait. Capturing the moment is undoubtedly a dream that is romanticized but not really discussed otherwise. So instead of going out to find those moments, why not make them come to you.
Photographers who love taking portraits have most likely experimented with a variety of focal lengths; or they're at least curious about what each does for the genre. Popular focal lengths include 85mm, but in the past few years 50mm and 35mm lenses have become better and better when it comes to portraiture.