Look, we’re not born knowing how to do everything. Some things needs to be learned. How to dress for the job you want, rather than the job you have, for example. Or when to laugh at a Shakespeare comedy on a school trip (answer: when your teacher does).
And, for me, it was beards. Oh, I’m reasonably middle-aged: I knew how to grow one. I just rubbed my chin with a secret formula and pushed down hard from my jaw every morning – and voila!
No, the mystery was what to do with it once it was there, mangled, matted, and smelling vaguely of BBQ and coffee, on my face. If you look to Google for ideas, you get something like this:

I went for the bearded dragon look. It seemed the best fit for my head shape.