You can't do it

Nobody should tell anybody they cannot pursue their dreams or that their dreams are a bad idea. How many dreams have those nay-sayers killed that way? A perfect excuse for not changing anything in anybody’s life is being “realistic”.

“Those that say it can’t be done should get out of the way of those doing it”

Chinese Proverb

Withhold judgement

Whenever somebody shares a certain level of ambition or goal with you, do not criticise them for it. Being realistic is not the best start to achieving original outcomes, so why would you?

Why wouldn’t you be more of a cheerleader and a supporter? To start with, they thought it was important to share it with you. And being a cheerleader doesn’t cost you anything.

Of course, you can add some criticism and ask some questions. However, judging and telling anybody to stop following their dreams is not up to you; it is not your dream.

Be the cheerleader

Always support people with ambition, you might be the only one supporting them, and you might be the person they need to get them where they want to be. And if even if they do not make 100%, they had a great ride and achieved progress. That is something they learn from and use in the future.