To try to achieve something that will never happen
You can use this phrase in ………… language.
I think my parents never truly believed that I could make it as a professional athlete. They supported me in every possible way, but I’d say they thought I was chasing rainbows.
I wonder when he stops chasing rainbows and realizes that he needs to find a job with a stable income, move out from his parents’ house and start living a life.