In Inception, Cobb uses a totem to determine if he's currently in a dream or in reality, as the dreams are so vivid it's impossible to keep track.
The last few weeks my dreams have been so deep and fucked up that I am wondering if I need one myself. There is often a feeling of being late, in trouble, or someone trying to find me. I've checked my phone for the departure time of a flight that doesn't exist, tried to navigate my own bedroom thinking it's an unfamiliar hotel room, and started cleaning.
Most recently, a recurring dream that combined the characteristics of two exes and how they chose to end our relationship. I quickly realise how much of an idiot I am, but the totem would have been spinning endlessly because in reality I didn't grasp it until it was too late.