Delusions are different from plain old "overvalued ideas". Overvalued ideas can hold some doubt by those who hold them, but delusional people, on the other hand, will continue to believe regardless of evidence to the contrary, and be absolutely convinced that it is real.
Here's some of my favorites:
- If I take a really firm hand with the person who is taking care of my (drycleaning, food, paperwork, child) and intimidate them, then they will take better care of my (drycleaning, food, paperwork, child)
- Nobody will mind if I park my car in the bicycle lane, just this once.
- It's just one more child. How much more work can one more child be?
- If I drive this vehicle, women will want me, and other people will be impressed.
- Really tight clothes make me look thinner.
- Really baggy clothes make me look thinner.
- If I wear my daughter's/son's clothing, I'll look cool.
- It's good fat.
- My lotto number is due to win.
- Every student deserves an A.
- My doggie is a member of my family; members of your family are allowed in coffeeshops/stores/restaurants; ergo, my doggie has the right to be in a coffeeshop/store/restaurant.
- I love animals. That's why I hunt.
- If I drive 5 mph hour under the speed limit, I will make the road safer for everyone else.
- Our friends who are vegetarians or require Kosher meals won't mind eating a bowl of iceberg lettuce while the rest of us eat three-course meals.
- My child does not lie.
- Intelligent Design is a sound, scientific theory.
- I know that research shows that people on cell phones are unable to attend to driving, but I'm the exception.