I would think having the ability to raise 18mo of funds to deposit in a bank already puts one in a small (and quite fortunate) group. True, this ability can come from diligence and careful financial planning, but there will always be external factors that could preclude this ability to save up in the first place.

Besides that, the more reckless half of myself is reminded of this Oscar Wilde quip: "Anyone who lives within their means suffers from a lack of imagination."