Be under the illusion that negative spoken language
Used to describe having a mistaken belief.
You're under the illusion that he has feelings for you.
He's under the illusion that he will be the only one to be chosen for that position.
Many people choose to be under the illusion to escape from the painful reality.
They're under the illusion that the project will be completed on time.
To daydream
Used to descibe someone or something fancy or colorful
Said when someone believes in unrealistic or fanciful ideas that is impossible to happen
Make someone or something fancier, more exciting or interesting
Impossible or unrealistic dreams, hopes, or plans