I especially agree with this when it comes to traveling or spending money on experiences and memories. Or maybe a possession we'll really value and use a lot. I never end up regretting money spent on vacations or on my favorite things.
However, I do think it needs to be within moderation. There is no point in spending money on things you don't really need or like. Otherwise- you start to realize you are trading your time and LIFE away to own things that will never bring you happiness. I am a firm believer in the more you own, the more your possessions own YOU.