I love the movie "Parenthood", and one of my favorite scenes is the grandmother telling the RollerCoaster parable: "You know, it was just so interesting to me that a ride could make me feel so frightened, so sick, so excited, so scared, so safe, and so thrilled, altogether! Some didn't like it. They wanted to go on the merry-go-round. That just goes around. Nothing. I like the roller coaster. You get more out of it."
Put another way, if you don't like the rollercoaster, it's unlikely you're going to enjoy the life of an entrepreneur.