Our dear old Apple Inc has unveiled iOS 7: a radical overhaul of the company’s mobile design language and a renewed emphasis on how apps feel in motion over how they look on a static screen.

This presents third party software developers with a challenge: since graphical ornamentation has dominated the platform for such a long time, how do we migrate our products to the new world? And how do we migrate our selves? After all, we all liked the old look and spent years learning from it and emulating it. How could we have been wrong to do so?

We weren’t. I hate to say this, but there’s no universal truth in design. The old style wasn’t fatally flawed, and that’s not why it reached the end of its life at Apple. Product design is a tangled nest of features, storytelling, fashion, marketing, and technological constraint. It’s applied psychology. So it’s important to acknowledge where our love for the baubled aesthetic of iPhone OS 1.0 through iOS 6.1.4 came from, where our current displeasure is sourced, and why we need to adapt.

Why did we love the old style? It’s pretty simple: we love shiny, rounded surfaces and bright colors, and the old OS had those in spades. It was one of the most visually decorative operating systems of all time, and our appreciation for it was as natural and universal as our love of warm weather, vocal harmonies, and the smell of ripe strawberries. It looks great in screenshots.

iOS 7 has a lot less of that roundness and shininess. It doesn’t look like the hood (or the interior) of a classic car any longer. In motion and interactivity it’s way cooler and bubblier than the iPhone has ever been before, so you can tell why Apple has pushed video demos so hard on their marketing site, but it’s lacking some of the characteristics we found so appealing. It has fewer bulging surfaces as the old plastic buttons and toolbars are smoothed out. It has fewer rounded corners as more screen elements stretch from edge to edge.

But honestly, of all the changes we’ve seen, how many are contrary to the basic psychology of visual design? Nothing unveiled at WWDC 2013 actually makes you cringe (and don’t make me link to pictures that will actually make you cringe to prove you a hyperbole abuser). It has more of the bright colors we love. The old inner shadows, drop shadows, bevels, and gradients that muted the old aesthetic are gone. It’s the first truly Retina iPhone OS, and more than just allowing the team to use smaller fonts while retaining legibility, it makes each pixel work harder to earn its keep. Color and shape do all the talking now, and the blurred translucency of the interface allows the color to permeate the screen more than ever before.

Where keyboards, pickers, and action sheets were once imposing screen elements with a lot of personality of their own, they now reflect the personality of their environment. Your bright red app won’t have a dull blue-gray keyboard anymore; it’ll have a light red keyboard as the bits of UI beneath it shine through. If your app uses a lot of wood textures, the standard action sheets won’t look out of character because they’re no longer plastic. No matter what you do with your apps, iOS 7’s default visual language will be a better complement.

But even if you accept my assertion that the new visual style is not inherently ugly, how do you explain the strong gut reaction against it? Why are so many of us calling foul? Why is it going to be so hard for us to adjust?

Familiarity bias. Familiarity bias and loss aversion. We love what we know and we’re afraid of what we don’t, so we don’t want to see our old friend replaced with this new thing. It’s irrational, but it’s human nature. When we look at our parents and grandparents we don’t see a crowd of pudgy gray-haired wrinkle factories… we see our history. We love them even when they start smelling weird and wheezing all the time. We wouldn’t dream of replacing them.

Our mistaking a familiarity bias for inherent superiority is where our gut reaction against iOS 7 comes from. It’s a kind of xenophobia. Apple took our beloved iPhone and gave it back to us a stranger. Still walks and talks the same, still the heart and soul we love; just not the face we knew.

This rejection of the unfamiliar will fade over time, just as the weirdness fades after a friend changes their hairstyle or starts wearing glasses. The casual and uncommitted user, the person who bought an iPhone because their friends all have one, will embrace the change pretty easily. But as people who live and breathe iOS, our transition will be harder.

How do we transition our work? The same way we did it in the first place. The majority of good UI design done in the world is done in service of making something new feel like something familiar. That’s why we follow platform guidelines and idioms: familiarity is intuitiveness. We want to make our customers feel as comfortable using our apps as they do using the ones that came with the phone, so we cater to the platform rather than inventing UI from whole cloth.

Apple just reset the baseline for what is considered native. They’re changing the definition of familiarity. Like a government moving to the metric system or ridding itself of the penny, this change will cause a lot of difficulty for small businesses and piss off a lot of old-timers. But it’s ultimately for the best. iOS 7 is a new platform for us, and it’s time to port our iOS 6 apps.

Best to embrace it, the good and the bad, and get back to work.