Been using Linux for 5 years now and I will never go back to Windows.
This laptop started life with Win7 pro, the first thing I did was dual boot it with Linux Mint to see what Linux was like now (years ago I had played with Mandrake and found it OK. but a lot of software that I needed not available so was just a plaything).
The laptop gradually changed from booting into Windows with the occasional foray into Linux to booting Linux daily with the occasional foray into Windows, eventually Windows was hardly ever used.
I replaced the hard drive a couple of years ago and didn't bother dual booting, it's Mint all the way with Windows (7 and XP) living on in VMs.
One thing I found when replacing the disk was all I had to do was copy my /home partition (including hidden files) to the new drive and the new Mint install (now on 17.3) found it and used it --- all my files and program settings were there when I booted up the new install --- very useful!
Linux runs just about everything I need (some Windows only stuff under Wine) and the only program that doesn't like Wine (a program for drawing circuit diagrams) runs fine in the VM. Printer, scanner, WiFi, 3G dongle all worked no bother (printing in Linux was very hit and miss years ago)
So yes, some of us didn't go back to Windows, of course YMMV ---- Linux isn't perfect and will not work for everybody but for me it does everything I need.