I starting investing in mutual funds in 2007 after reading "A Random Walk Down Wall Street". The book taught me the difference between systematic and non-systematic risk in equities and convinced me that buying equities was a good investment for retirement. The book also convinced me that one cannot time the market. So I took my existing savings and bought some mutual funds.
Then the 2008 financial crash hit.
This week my investments finally recovered. I now have an XIRR of 0.08% per year. Since I measure my value in Canadian dollars, it took me longer to recover than those measuring in US dollars or Euros. The Canadian dollar has appreciated quite a bit in the last six years.
I stand by my financial choices. After all, I will have far more in future saving than I have in past savings.