I never really liked XP all that much. the UI was garbage, and theming it to Classic you might as well just go back to Windows 98 SE. Windows 98 SE was up until 2011 my favorite OS, just as in 2020 my old Samsung phones running TouchWiz are my favorite phones. I have a ton of experience in Win98SE, and it was super fast running on systems designed for XP running 1GB RAM. I managed to keep Flash working up to version 10 via the self-extracting archive to enable those goofy Facebook games to work in the 'unsupported' OS.
Windows 98 finally died with HTTPS killing the ability to browse and login to those sites. I for a short time worked around it by going to
http://m.facebook.com back when it would produce a text-based version, after Facebook killed their 'Facebook Lite' website, but eventually that got updated to look like the phone app and broke compatibility with SeaMonkey 1.1 and Firefox 2.2.
By that time the better looking (to me) Vista and later 7 came out. In 2012, however, I got spoiled by Mac OS X Mountain Lion having bought my first MacBook Pro after being spoiled by an iPhone 3GS my boss handed me (get rid of that awful Nokia or you're fired, I can't afford losing calls from you due to its horrid battery) and I later got an iPhone 4 to enjoy retina for the first time.
However, my memories of Windows 98 SE remain my fondest. It was to me the fastest, most stable platform I used. I HATED XP. It looked awful, it was super slow to boot, and tended to BSoD far too often. It was a major system resource hog, and it was trying to do far too much and many options were dumbed down 'for the masses'. The only thing I remember fondly of it was title.wma on first-boot, but that song track was also on the Internet Explorer 3.01 Starter Pack disc that came with Windows 95. Many assume it was exclusive to XP.
Many other things XP did made itself a nightmare to use. Office with its Clippy assistant, BonziBuddy finding its way onto my system, Messenger spam, the Klez worm, and the fisher price UI design. One could call it proto-skeuomorphism but Apple did far better with that than Microsoft ever could.