But now put yourself in their place. You are in a room, walking down the street, or sitting on a bench. A strange person comes over to you, gets in your personal space, and reaches out to touch you. How many of us would be okay with that? Most likely, the police would be dragging the culprit away with us running in the opposite direction.
Most animals don't wear a warning sign, like our little friend here, so when it comes to approaching animals you don't know, be cautious. Ask the owner if they are safe to pet. If their friendly, be slow, let them have a chance to get to know you, and don't put your face by any animal you are not 100% sure about. Being cautious and respectful of their personal space, will ensure that both of you will have a safe & enjoyable encounter.