Saturn is a slow moving outer planet. He takes about 29 years to cover what the Moon does in about 29 days. This makes his movements serious and important. A second chance to get a Saturn transit right will be a long time coming. We want to get it right now.
Saturn is the 2nd largest planet - a planet of contraction (Jupiter, the largest planet, is the planet of expansion so we expand a little more than we contract) - he's about boundaries, responsibilities, karma, commitments, self-control, solitude - the stuff that defines (meaning = outlines) us.