How do you feel about changing job constantly?

Some people prefer to have a so-called “stable" job. In this case, they usually work in the same company or institution, the same position (can be promoted to a higher one, but basically do the same job), and till their retirement. This is what sounds like a "really good job". However, from my observation, changing jobs is a commonplace among my friends and colleagues. We don't see this as "unstable", but instead as a new chance, and we are open to jobs in different fields. What about you? Let's discuss.