You can't fly jets if you're colourblind

Originated from the movie "Little miss sunshine".

When you dreamed of something for a long time that you wanna accomplish (eg: dream job, or other goals) but later on you realise you can't achieve it because of a disability you have and/or other things stopping or preventing you from doing that spesific thing.

Person 1: I wanna become a pilot!

Person 2: But aren't you colourblind?
Person 1: Yes, why?
Person 2: You know you can't fly jets if you're colourblind.