Eyebrows

At what age does one normally begin to “feel" their eyebrows? Is this a common occurrence or is it just me. At first I believed it was my crappy new glasses. Perhaps they sat on my face in just such a way as to ever so gently brush against a few eyebrow hairs and make me know – all day long – that my eyebrows were indeed on my face. But I checked. Nope, not it. My next thought was – “Oh My Gosh, I have gotten to the age where I have those out of control, long, unruly, wild, old man eyebrows?” God forbid! So I checked. Nope, not it. But just to make sure that was not the problem I took my handy dandy sideburn trimmer (well really it was my husband's) and used the long trim attachment to trim those annoyances down in case I missed one.  I am half blind, so missing one just by looking in the mirror was a very real possibility. What happened you ask? I used the wrong side and accidentally shaved my eyebrows completely off! Curses! Good thing I am half blind and have to wear glasses that cover my, shall we say, lack of eyebrows! But it was then I noticed - that I STILL noticed them. They were completely gone, there were no hairs to rub on my glasses, there were obviously no wild strays, so there was no rational reason I could think of to be in this quandary – nevertheless, I could still FEEL them. So I ask again, at what age does one normally start to “feel” their eyebrows??!! Maybe Groucho Marx can answer my question.