– “You can do anything in the world that you want.”
You can’t predict what I might want, so it’s wrong to make an a priori assertion about the possibility of what I want. What if I want to not want anything? Since that leads to paradox, I can’t very well do it. That’s only an example, and the most obvious one I could think of; there are many other possible paradoxes which invalidate this assertion.
– “You can do anything you put your mind to it.”
You can’t do anything by merely putting your mind to it. You have to understand what’s possible, how you can use what’s possible to achieve your goal, and how to organize your goals so as not to interfere with one another. Then you have to actually go ahead and do stuff.
– “Any goal you set for yourself can be achieved.”
If I set a goal for myself to travel back in time and kill my grandfather before he has kids, then I will fail in that goal. Again, there’s a paradox involved. If I set a goal to grow until I’m 7 feet tall, I will fail in that goal as well; there is no known mechanism to make me grow any talller than I already have (which is quite enough, thanks!) Even without paradox, many things are just not possible as far as we know.
It’s ok for a person to attempt the impossible, but a person shouldn’t plan yer life around it. That will lead to a failed life and a miserable. That’s why I’m against saying stuff like this to children, because they might take that horsepucky seriously and start planning their lives around some Quixotic optimization. Let’s not keep “inspiring” young folks with visions of impossible ideals when we could be showing them what’s good in life.
Remember: “Aim for the Stars- even if you miss, you’ll die alone in the cold emptiness of space.”