Wishful Thinking
The Fallacy
Believing something is true just because you really, really want it to be true.
Why it's wrong
Wanting a unicorn very badly will not make a unicorn appear in your backyard.
Example
I didn't study for my test, but I really want to get an A, so I'm sure I'll get an A anyway.
What the Fallacy?! (ELI5 Edition)