At some point parents have to realise the same.
Not all potential Steven Hawking's want to do physics: is it a waste if a potential Einstein actually prefers a life as a beachcomber?
As a parent would you prefer to have a rich, important, famous depressive, or a poor underachieving happy nobody? (Assuming that the child has the skill to do either).
The trick at this point is raising them so that when they get to your advanced age they don't look back and say "I wish that ...".
In truth, it's about attempting to put an old head on young shoulders.
In the past that has just been a procedure that invariably fails and we all end up getting on with life how we see fit - usually repeating all the mistakes of our forefathers and adding a few new ones to boot. But these days it is essential (in this country) that one's children achieve as there will be no more social housing for those who choose to be florists, no more NHS for those who choose to surrender their health, and no more hand outs for those who fail to secure an income.
But let's get this straight: It is the State that insists this by encouraging strict schools that are otherwise called academies or free schools. My son's cousin goes to an Ark academy and is now a thoroughly depressed child (you get detentions for incorrect margins in your books) and I believe that this "all stick and no carrot" approach is completely counter-productive.
In contrast, I am astounded by how little homework my son's school doles out and all in all it is more like a social gathering than a school. He actually enjoys going (WTF!) and didn't even miss a day through sickness in his first year - even with a major drama or 2. But his school has graduates that get into Oxbridge (2 or 3 a year) so they certainly know how to identify and nurture those with potential.
I, above all, know my son's potential and while I have been wholly unsuccessful in convincing him of it, he is doing remarkably well nonetheless. However, I am not about to stop encouraging him to do even better.