At the time of injury, a puncture wound may not appear to be as bad as a surface wound. It's a smaller hole, rather than a gash, and it may not bleed as much. Maybe you stepped on a nail on a commercial property or got involved in a car accident or got bitten by a dog. No matter how it happened, it's important to take these wounds very seriously.
The issue is that puncture wounds go deep below the surface of the skin, into muscle and other tissue, and the item that caused the wound can press bacteria far into that wound. This massively increases the odds of an infection. A surface wound is much easier to clean. When bacteria become trapped -- especially when a puncture wound is not allowed to bleed very much -- it can lead to serious complications that are worse than the initial injury.