One is to listen to your gut, no matter how good something sounds on paper. The second is that you're generally better off sticking with what you know. And the third is that sometimes your best investments are the ones you don't make.
gut
/ɡʌt/
the long tube in the body of a person or animal, through which food moves during the process of digesting food
ruột
to stick
/stɪk/
to cause something to become fixed, for example with glue or another similar substance
