Dreams can be anything from immensely satisfying, to bittersweet right through to absolutely terrifying - and everything else in between.
Perhaps the most perplexing of all dream models are recurring dreams - in particular if they always feature the same person, over and over again.
Maybe you're happy to see this person. Or perhaps they're your sworn nemesis. Either way, their repeat dream-time cameos DO mean something, apparently.
While it's not uncommon to have recurring dreams (two thirds of us experience them) the reasons behind them are, psychologically, interesting.
What does it all mean?
Luckily, the purpose behind someone cropping up repeatedly in your dreams isn't as literal as you many think it is. I.e. they're not a sign you'll be spending the rest of your life with them (sorry).
"The model of the mind is very true to the idea of a computer," clinical psychologist Dr John Mayer told Elite Daily.
"When we go to sleep, that little computer will keep churning. It doesn't just turn off and stop. We have a perception that we're blank when we sleep - but [the brain] keeps going."
Dr Mayer adds we should not take someone cropping up in our dreams repeatedly in a literal way. That person is instead symbolising a certain stress or anxiety we are going through.
"The dreams are usually not exactly the same each time, but the recurring theme is usually something in your head that is somehow unresolved. It just keeps repeating over and over again in that computer.
"So if the data is the same in the machine, you need to replace it with other data, or resolve that conflict, or solve that problem."
And if you're having a dream that's particularly upsetting, Dr Mayer advises finishing it off yourself by putting your head down and ending the dream in an "unexpected and positive way."