What if we're living in a computer simulation?

Have you ever wondered if life is not exactly what it's cracked up to be? OK, let's take that thought a little further. Have you ever suffered from an identity crisis? One in which you suspected that you're not a real person, but instead an extremely sophisticated computer simulation of a real person produced by an immensely more developed civilisation than that which we take to be our own? It's just possible that I lost you on that last point, but stay with me, because the reality we take for granted is coming under increasing technological and theoretical threat. Earlier this month in an office block in Euston, I put on a virtual reality (VR) headset and began playing a prototype of a game developed by a company called Dream Reality Interactive.