Parking Space Lines

Lots of people go to a shopping center on a busy day and drive around looking for a parking space.  At times the only one available is where a car parked over the line into the last empty space.  The thought goes in your head, HOW CAN THIS PERSON PARK OVER THE LINE?  So you park in the space, but now you have to park slanted and over the line.  What you just did might have happened because of one person who parked in a spot over the line due to a car a long time ago.  This affects the next person trying to park in the spot between the lines.  If the person who parked in the spot never went over the line, then everybody else would not go over the line.  In a perfect world the parking space lines are there for cars to park in between and not on or over them.