Thinking mobile first forces you to only keep what matters in our sites. We have to think about usability & content because people on mobile have very little time and screen space.

— Jeffrey Zeldman, “Content First” talk at An Event Apart, as noted by Luke Wroblewski, 2012.

The line is from Luke Wroblewski’s notes on Jeffrey Zeldman’s “Content First” talk at An Event Apart in 2012. We were building our first mobile-first themes at the time, and the sentence put into words why: the layout doesn’t get smaller, the content gets more important.