it's kind of like if someone gave you a ferrari for your first car and you'd never had any other car, and you didn't know much about cars. people would comment on your car regularly - 'wow, cool car', etc. but to you it was just a car. it started in the morning when you needed it to and hadn't left you stranded at any time.
these kids were ferraris. they were exceptional but due to no point of reference to compare with, the parents just took for granted that all kids were like this. didn't everyone have a ferrari? are ferraris cooler than other cars?
maybe you had really wanted a pickup or a suburban and all you see is the lack of space to store stuff. maybe you're scared of driving fast and all this thing seems to do is accelerate.
appreciate your ferraris. recognize them. praise the good stuff generally and generously (you are the coolest kid around! i think you're great! thanks for such a great day/week!) and criticize specifically (i can't allow you to do/say that. we don't hit/bite, etc.). so you're creating an ambience of positivity with this general 'gee, you're super' and in that context you are able to work on the fact that your ferrari doesn't have much trunk space more specifically without losing sight of its 'ferrariness'.
addendum: some days we all think we have a ferrari, or if we told him or her enough good stuff that he or she would become a ferrari. don't lie to your kids to improve their self esteem. just honestly enjoy them, whatever they may be. that is the truest form of love, to love without condition, just because you 'own' this kid you love him, because she's yours you will never not love her. so i guess i'm looking for that balance: of positivity and truth, of appreciation with no conditions - i love you because you're you. this level of contentment is a blessing i wish i could instill/inject/impart into so many parents - it's not what they do or where they go or how well they do - if they are yours, you love them, and i know it, so let them know it, then all the rest, like growing up and being good kids and getting good grades and going to a good school and marrying the right person and having you some grandkids...that's all just icing on the cake.