If I were Mr. Miyagi and I were reading this aloud, you might expect this to be about greasy pieces of potato, or my ability to catch flying insects with chopsticks. Either option not being the case, I’ll begin.
I just realized how much I appreciate the invention of the button-up fly.
As little as I actually use the mid-section’s trap door, button-up or otherwise, I would still like to extend a shake, (or two), of gratitude to the, I assume man, who created the button-up fly.
And, speaking of extending things…when was the last time you actually used a zip-up fly as directed? Why would I, or any guy, try to feed the most sensitive portion of the male body through a tight opening lined with cold metal teeth?

Danger, Will Robinson! Danger!
I much prefer the “up-and-over” tilt.
This is where you undo your belt, open your fly and only pull the front of your pants down, leaving your ass concealed. It is more conducive to the process and you’re less likely to leave evidence on the inseam.
Regardless of which method you use, the next time you approach the porcelain with a button-up fly, take a moment and be thankful…for the buttons.