Have you ever seen a cartoon where someone thinks their friend is actually a bad guy in disguise? Well, sometimes people feel like that in real life, even though it's not true! That's what delusional misidentification syndrome is.
When someone has this syndrome, they might think that people they know really well aren't who they say they are. They might think a stranger is actually someone they know, or that someone they know really well is an imposter.
It's kind of like when you see a magic trick and can't figure out how the person did it. But instead of being fun, it can be really scary and confusing for the person experiencing it.
It's important to remember that people with delusional misidentification syndrome can't help feeling the way they do. It's not their fault and they need help from doctors to feel better.