It's not easy, but one way to try and maintain sanity is by taking a worldwide view of every situation.
Both Ted Cruz and John Kasich have fallen by the wayside, while Donald Trump dashed to the finishing line of Republican Party nomination for the US presidential race in 2016.
Some people run simply out of ego or greed. The publicity that attends a presidential bid can garner even a failed candidate a book contract, a television gig, or a well-paid speaking career (or perhaps all three). Trump ran on the basis of his celebrity.