One thing most parents don't talk about? How vastly underrepresented stay-at-home dads are. Think about it: they deal with a lot of the same troubles stay-at-home moms run into. And while a quick Google search will yield hundreds of personal essays and posts dedicated to the female version, the amount of literature on stay-at-home dads is sorely lacking.

So if you ever come across one of these dads at the PTA meeting or pushing his kiddos on the swings at the park, make sure you go up and introduce yourself. After all, you never know exactly what you can learn from another parent, regardless of whether they're male or female.

Looking for a few more reasons to approach that smiling face the next time you're out? We've laid out why you should give a friendly wave in that dad's direction.