Advice from a 95 years old about investing in Bitcoin

My grandfather is 95 years old, completely deaf and in a wheelchair. He's still reading a lot about economics and finance, and I told him that I was working for a company making hardware wallets for crypto currencies. A few days later I got this handwritten letter where he advised me about investing in Bitcoin. For those not reading French, he says "when Rostchild was asked how he became rich by trading on the stock exchange he always replied 'I always sold too early". That is man is a genius.