Why did the 2008 financial crisis start?

This infomation is from https://www.bbc.co.uk/news/business-44952925 :

The global financial crisis had been precipitated in 2007 with a subprime mortgage crisis in the United States and developed into a full-blown global crash after Lehman Brothers went under.

How did the 2008 financial crisis effect your finances? This information is from https://www.bbc.co.uk/news/business-45483636. :

The average UK house price fell from a pre-crisis peak of £190,032 in September 2007 to a low of £154,452 in March 2009, according to data from the Office for National Statistics and the Land Registry. Since then, the price of an average house has recovered to £228,384. Is that good news for homeowners? Not necessarily. There's no such thing as an average house, and for homeowners there's been a real north-south divide in the last decade in terms of property prices.

My thoughts :

I think that the 2008 financial crisis did effect us humans now because, it was started first with risky morgage loans. I think it has also effected the way we as humans consider buying and selling things. he 2008 financial crisis led to the Great Recession.

Great Recession = The Great Recession was a period of general economic decline observed in world markets during the late 2000s and early 2010s.

UK = United Kingdom