Pressure is the force divided by the area.
If somebody stand on you with both bare feet, it may not be so bad, but if they put all of their weight on a very small heel, the force is concentrated over a very small area, so the pressure would be very high.
This is why it is so easy for a needle to break the skin. The tip of the needle has a very small area, so the pressure can be very high.
A physics teacher may lay down on a bed with many, many nails, but never on just one nail. Why?