This is a pretty good theory. 2005 was a big year for me as well. I was studying for an MFA and had a nervous breakdown from stress / alcohol consumption / heavy cannabis use for years in Jan 2005. I thought that TV and radio were talking about me, that my fellow students were conspiring against me, heard voices in my head. I received counselling for the first half of 2005.
I started down the path of drug use etc because in 2001, when I moved into a student house, I broke up with my girlfriend because a) I didn't think the debauched environment was appropriate for her to be around and b) my family and some friends thought our age difference was inappropriate (I was 18, she was 16 when we started going out but 4 months later we were 19 and 16). So I broke up with her and was pretty shitty to her to make sure she'd stay away. I built a kind of emotional wall around me that only snapped in 2005.
When I was receiving counselling I bumped into my ex at a party in April 2005 or so (the first time I'd seen her since we broke up). We ended up smooching even though she had a boyfriend (who was there at the party, a guy even older than me who she'd been with since we broke up in Sep 01). She told me she thought about me every day. I told her about my breakdown and about how I hadn't been in a relationship since my one with her. She gave some strong signals that she wanted to have sex. I didn't think that was appropriate with her boyfriend being in the house so I got her number and said I'd call the next day to see if she still felt the same way.
When I called her in the cold light of day she told me she thought she'd been a dick and regretted our kissing. She texted me a few times seemingly inviting me to try and "win" her from her boyfriend in the weeks ahead but I was still too fragile and besides I'm quite conservative about relationships really - either you're with someone or you're not imo. A month or two later I started going out with another girl so things fizzled out with my ex.
I know this is all a bit random but it has been therapeutic to type out if nothing else. Anyone who's had one will know there's nothing glitchier than a nervous breakdown. Ultimately though I thought my breakdown was a positive thing. It helped me sort a lot of issues out. In the summer of 2006 I met the girl who would become my wife who I love and am happily married to with kids.
To be honest, the marker for the "world changing" in my mind was Sep 2001. That's when I broke up with my ex, got into substance abuse and of course 9/11 and the war on terror happened. Interesting that this seems to be a common mental phenomenon with others as well