What The Flux Capacitor!

(I work doing PC and electronic maintenance at a large company. I am called into an office to check out a malfunctioning label maker.)

Me: “So, what’s the problem?”

Customer: “It isn’t working; I can’t get it to print.”

(I take a look at the document and print out the labels effortlessly.)

Me: “Seems to be working fine.”

Customer: “Well, it wasn’t working yesterday when I needed it.”

Me: “I see. You might have just needed a simple restart. It seems to be working now. Is there anything else you need.”

Customer: “Well, why wasn’t it working yesterday?”

Me: “I can’t be sure since it seems to be working now. Unless you were doing something different?”

Customer: “No, but I needed it to work yesterday.”

Me: “Well, I’m sorry, but I can’t fix it yesterday.”

Customer: “Why not?”

Me: “Because I don’t have a time machine.”