When somebody says something about the practical problems of an idea you have, what is your reaction? How do you feel? What do you think?
For example, say after you suggest this great idea somebody says something like, "Well, that won't work too well because of this, this, and this. And have you thought about this? If you do that, then how will that other thing work? Aren't you forgetting about this, this and this?" and so on. Like if they bring up reasons why your idea might not work.