If you don't have a clear passion and somebody blithely tells you to go follow that passion, I think you have the right to give that person the middle finger. Because that's like somebody telling you that all you need in order to lose weight is to be thin, or all you need in order to have a great sex life is be multiorgasmic: That doesn't help!
I'm generally a pretty passionate person myself, but not every single day. Sometimes I have no idea where my passion has gone off to. I don't always feel actively inspired, nor do I always feel certain about what to do next. But I don't sit around waiting for passion to strike me. I keep working steadily, because I believe it is our privilege as humans to keep making things for as long as we live, and because I enjoy making things. Most of all, I keep working because I trust that creativity is always trying to find me, even when I have lost sight of it.