Even though you may not know too much about the shortest day of the year, it stands to reason that it would make sense for you to feel that this would be the point where the earth is the furthest point away from the sun. After all, it would mean that it was darker for longer if this was the case, but the problem with that approach is simply that the sun and the earth are not willing to play ball.
In actual fact, the day of the winter solstice is actually the point where the earth and the sun are at their closest, and this just simply goes against absolutely everything and anything that seems to make sense in the world. This is all connected to angles and the rotation of the earth, so if you want to blame anything for this bizarre point, then blame physics.