Global events might have you depressed about investing. But AMP's Shane Oliver tells punters to keep their eyes on the prize. 9 things to keep in mind to invest successfully in tough times You’re reading a free article with opinions that may differ from The Motley Fool’s Premium Investing Services. Become a Motley Fool member today to get instant access to our top analyst recommendations, in-depth research, investing resources , and more. Learn More There are articles everywhere, including on this website, that tell you to buy this and buy that. But it's easier said than done when the world…