Is investment relies on your own instincs?

I have encountered lots of people that they make their own decision about investment by their own instincts and got into a bad loss. Because their decision was not fully fortified by making their own research first. Basically when you make an investment, it is a gamble that there is a possibility that your investment could turn into zero. So better be sure that you won't end like this. Better make your own research first regarding the investment that you are entering with and hopefully you could come into a good result.