Some do it because they get mad.
Some have it thrust upon them.
And some, well, they allow themselves to get persuaded in the most ticklish of ways.
I was enthralled, you see, by the experience of a diehard Apple user who was suddenly enticed to the forbidden lands.
Mark Frauenfelder has been using Mac computers for a long time. He started with Windows PCs, but that happened to a lot of people in olden times.
His abandonment of Windows in favor of a Mac in 2002 was so absolute that he appeared in an Apple ad. In it, he described the "clunky world" of Windows.
"It's like being stuck in a bad relationship," he said in the ad. In those days, it really was.
He explained in Boing Boing how thoroughly embedded he became in Apple's superior sense of design and basic humanity.
Recently, there came a strange day.
A representative for Gateway -- and the encouragement of Frauenfelder's 17-year-old gamer daughter -- enticed him into trying its laptops risen from the grave. In this case, a Creator Series 15.6 inch Notebook.
Surely such a committed Mac user couldn't stoop to such a déclassé life.
Yet Frauenfelder began to feel frissons of pleasure. He enjoyed the numerical keypad and the sudden lack of bloatware.
Ignore something for 18 years and perhaps it does finally manage to get better.
Windows 10 seemed to surprise him. And not in the negative ways it's surprised those who have used Windows for many years.
The search function delighted him. It was much faster than OS X Spotlight. Working in the cloud made slipping from one OS to another quite easy.
And then there was the price. $800 for a laptop that enjoyed barely a spinning fan.
This contrasts with the latest MacBook Air, for example. Mine makes lots of noises merely at the idea of tolerating the Mail Online site, which some might find understandable.
Frauenfelder found himself comparing his new MacBook Pro, configured to his needs for a total of $3,000. It, too, appears to have a fan that hums and hisses as often as New York air conditioning in August.
But can the price be a sufficient reason? Surely there are downsides to this far cheaper Gateway?
Frauenfelder identified merely two deficiencies. First, the trackpad, which isn't remotely as delightful as his MacBook's. He solved this, however, by using a wireless mouse.
And then there was his preference for Mac's Finder over Windows' File Explorer. He's technically adroit enough to fiddle with a few things and make the whole thing look and function like a Mac. His reason? "Because I suspect that I need to get used to Windows," he said.
That's when I began to worry. On behalf of Apple fanpersons, you understand.
Many often point to rational reasons why they won't switch from one way of computer-living to another.
Yet Microsoft has clearly watched Apple's success, wondered about all this human-friendly stuff that Cupertino has peddled since its inception, and decided there must be something to it.
Using Macs isn't merely about being embedded in a way of doing things. It's about a strange feeling of respect and emotional commitment to a brand that has helped so many come to terms with our new nerdly kingdom. And even enjoy it.
Fraudenfelder's struggle sounds emotional, rather than rational.
Hark at Freuenfelder's tortured conclusion: "I think I'm going to keep using Windows from now on." The italics are his, as is his angst.
"I do feel weird about it," he said of his struggle. "It feels like switching political parties. I've been a loyal Mac user for almost 20 years."
One of the great differences -- so little understood for so long -- between Mac and Windows users was the contrast between emotional involvement and mere utilitarian necessity.
Microsoft bored you with productivity. Apple enchanted you with humor, empathy, and sheer humane simplicity.
The gap has unquestionably closed, yet I couldn't help but chuckle at Frauenfelder's beautifully rational attempt to persuade himself that it's time to leave his true love behind.
He said: "Windows has evolved into an excellent operating system. This, and the fact that Windows computers are much less expensive than Apple computers, is enough to put me in the Windows camp."
Many people go camping for a few days. Few manage to live in tents for the majority of their lives.
My wife has been a Windows user for all her days and has few complaints about Windows 10, except for the painfully heavy Dell laptop she's forced to use.
I, like Frauenfelder, have been using Macs for a long, long time. Would price and a more human Windows persuade me to switch? I fear not.
I don't think my emotions could handle it. I'm delicate, don't you know?