I don't get it - I tried concentrating. Is this a game or someone pretending it happened in real-life?
It sounds like he changed his computer clock 4 years into the future, so the game thought 4 years had passed and no maintenance had been performed in that time frame... so everything is falling apart. and it remembered the overgrown status, so resetting the date did not undo the damage.
I remember an old HP free screensaver ploy: They had this realistic looking goldfish, and you would have to feed it regularly for it to flourish. If you didn't feed it for a week, it would die.
You had to 'buy' food and 'fun accessories' using credits. You got a credit for each page that you printed out. (=tons of people doing unnecessary printjobs so they could feed their fish or buy plants & accessories for in the background)
One of my co-workers had been playing around with this stupid fish for a week or two (figured out he got 'free' credits by using print-to-file). One day while he was out for lunch, we forwarded the clock on his computer a year. That resulted in a dead fish floating belly-up at the top of his screen since it had been a year since its last feeding. :-?
(In that case though, rolling back the date revived the fish again. Luckily for us.)