Seeking Alpha is a site that I visit daily; it means that much to me. I'm almost 89 and only got into investing in individual stocks about 10 years ago; previously was only in mutual funds.
I'm a geologist by profession and decided several years ago to follow the advice of W. Buffett and stick to what I know something about. So my investments are nearly 100% in oil/gas, weighted about 50/50 in E&P companies and pipeline MLP's.
Robert Powell, on MarketWatch recently wrote that after age 60 our financial smarts erode quickly, and conclude that I must be a rare exception. I invest only through the internet, Vanguard's Brokerage service. Wish I had gotten into this 20 years ago: I'd probably be a millionaire now.