You can, but you have to move to Africa and live alone for 3 years, contemplating the wish non-stop until you are allowed to come back to civilization and post your answer

I wish my Physics would do itself

Your homework now does itself as you sit back and relax. Bit sadly, since you pen and paper do not have brains, all of your answers are wrong

I wish I could sing better.

Congratulations, you can sing much better. So much better you win next year's Arias and Idols contests. It is because you have learned to shut your eyes when you sing, so you can close off audience reactions. Unfortunately, because you never recognise people when you keep your eyes closed, you annoy your adoring fans who think you don't care about them.

I wish I could afford to buy a new car that doesn't use so much petrol.

(Translation: I wish I could afford to buy a new automobile that doesn't use so much gas)

You can afford the car, but you can no longer afford the gas. Your shiny new sedan with the voice controls and sunroof isn't going anywhere. (And we say cars over here, too. )

I wish the customers at my job would be less rude to me.

The customers at your job are so nice, they refuse to leave, forcing you to continue to work 24/7 to please them.

I wish I could go to New Zealand.

Wow! You do get to New Zealand, which won the Oscar for the Best Supporting Country in the World. The trip is all you ever dreamed of seeing. The ridge of mountains used in LOTR, alone, was worth the expense and trouble. It will be something you will remember for the rest of your life. Unfortunately, you confused New Zealand with Australia, so they transport you to Botany Bay when you start discussing such matters as pavlovas and possums.

I wish I could run a car on something else besides petrol or LPG gas.

Congrats! Your car now runs on neither. It's the Flintstone's car!

I wish I was prepared for today.

Congradulations! You are now an Eagle scout!

I wish I could go see the Hobbit again

You can see the so-called "Hobbit" who lives next to your house again. He's just a short person though, so he's not really a hobbit, and you meant the movie called "The Hobbit", so you get what you wished for without getting what you wished for.

I wish I could easily think of a wish.

You now can think of nothing but wishes.

I wish was to the right of the post a reply field instead of in the "View more smilies" link.

Fantastic! A kind genie godfather - er - administrator causes your wish to be fulfilled. But some of the existing emoticons will disappear, unfortunately.

I wish that somewhere on this site I could find a list of codings for all the emoticons, so I know when to use :ym...: and when not to.

If you click "view more smilies" it'll give you a list of smilies and you simply have to click the one you want and it'll insert the code in the post reply box.
But when you do this you accidentally post them... when you only wanted to see the codes and the mods confuse you as a spammer.

I wish my laptop wasn't on the verge of crashing.

As of now, your laptop will no longer be in danger of crashing... it just did. And there is nothing you can do about it .

I wish I owned a Hobbit hole.

You do, but it's too small for you to fit inside.

I wish I could speak all the languages of the world.

You can, because all the world now speaks English. How boring.

I wish I could sing at least twice as good as I do now.