In 2008, the world was facing a really big problem with money. People were lending and borrowing money like crazy, and banks were giving out loans to people who couldn't pay them back. This meant that there was a lot of fake or imaginary money floating around, and not enough real money to pay for it all.
When too many people couldn't pay back their loans, the banks started to run out of money too. This meant that they couldn't give out more loans or invest in things like they used to. As a result, companies started to go bankrupt, people lost their jobs, and the whole economy started to crumble.
Governments and banks tried to fix the problem by injecting more money into the system, but this made things worse because it caused inflation (where prices for everything go up). Eventually, things got so bad that it became known as the Great Recession, and it took years for countries around the world to recover from it.
So basically, in 2008, people were being really irresponsible with money, and it caused a big problem that affected everyone. It was like everyone was pretending to have money they didn't really have, and when the truth came out, everything fell apart.