Your friend sounds like my kind of guy. I paid off my housing loan in 5 years, whereas the norm in my country is to stretch the loan for 20-30 years, refinance it whenever necessary and invest money in investments that will yield more than the mortgage interest rate. It works for my countrymen but I just hate the idea of being in debt. After I paid off my mortgage, I felt so much lighter and prouder of myself. There are many opportunities to earn money. I understand that nothing beats time in the market, but honestly, I don’t have to optimise every single dollar of mine. I value peace and clarity of mind more.