“Goodness is the only investment that never fails.”

~henry david thoreau

I think this statement means that wasting time and money isn't worth as much as goodness is. For example if you buy drugs. Such as marijuana you are spending $10 per gram. It may cost a little bit more depending what type. But at the end it isn't worth it. Because now you have no money, fake friends, less brain cells, and now you smell weird. What this is trying to say is don't spend your time and money in stupid things like drugs or luxuries.