About two years ago I received a letter in the mail. It was written in bold letters and filled with exclamation marks. It basically warned against wearing tight, extravagant print pants. It sounds logical now but they were all the rage at the time. The message closed with statement, ‘transparent light bulb pie,’ and was signed, ‘your future self.’ I completely forgot about the whole thing until this morning. I was out having a coffee with a girlfriend of mine. We’re just friends but I’m obviously pretty keen; I suspect she is too. We were talking about time travel and she said that she was going to make up a password; if she ever stumbled upon her future self she could just ask for verification; how else could she be sure it wasn’t a lookalike android? Immediately I thought of the letter. I asked her what she had in mind for a password; ‘transparent light bulb pie,’ she replied. I was absolutely taken aback; I couldn’t believe it. Surely I could’ve come up with a code word of my own. Hers wasn’t even very good.