Being a visionary billionaire and chief executive of three companies at once isn’t all fun and games, Elon Musk tweeted Sunday, describing “unrelenting stress” and suggesting he may be bipolar. Musk tweeted his replies to a number of questions on Twitter, starting with his response to a tweet that said he had “an amazing life.” “The reality is great highs, terrible lows and unrelenting stress,” Musk tweeted. “Don’t think people want to hear about the last two.” When someone else asked if he was bipolar, Musk replied “Yeah,” but then followed up with: “Maybe not medically tho. Dunno. Bad feelings correlate to bad events, so maybe real problem is getting carried away in what I sign up for.”via