Why Do Men Sprout Hairs in Weird Places with Age? (nytimes.com)

Roots. When that starts, its important to stay active. If you stay in one place too long you take root and it becomes much more difficult to move, even for the most trivial things. cf. all the "couch potato dad" tropes.

Indeed. My haircut routine now includes my tragus, the tops of my ears, and giving my eyebrows a good trim. Oh the joy.