People are sure about the return from an investment. However we were able to experience massive losses on some occasions which were completely unexpected. So, investment too kind of gamble. You'll invest today with the expectation to eat tomorrow, but you won't get the food. In such situation what can be done. For two days you weren't able to feed yourself, the next day your mind won't function perfectly to analyse the market. So, the importance of food is high than an investment.