Knock knock pick up lines have been around for a long time, and knock-knock pick-up lines are just one of the many variations out there. They are playful, witty, and can make a person feel special or flattered. However, it's important to use them in the right context and with the right person, as they can easily come across as cheesy or insincere. Some knock-knock pick-up lines can be corny, while others can be clever and charming. Ultimately, it's up to the individual to determine which lines work best for them and their situation. Remember to be respectful and have fun!