My Hobby:
Embedding NP-Complete problems in restaurant orders
[A menu is shown.]
Chotchkies Restaurant
Appetizers

• Mixed Fruit 2.15
• French Fries 2.75
• Side Salad 3.35
• Hot Wings 3.55
• Mozzarella Sticks 4.20
• Sampler Plate 5.80

Sandwiches

• Barbecue 6.55

[Megan, another person, and Cueball are sitting at a table. Cueball is holding the menu as well as a thick book and is ordering from a waiter. Megan is facepalming.]
Cueball: We’d like exactly $15.05 worth of appetizers, please.
Waiter: …Exactly? Uhh…
Cueball: Here, these papers on the knapsack problem might help you out.
Waiter: Listen, I have six other tables to get to—
Cueball: —As fast as possible, of course. Want something on traveling salesman?