Answer:
If only I hadn't lost my wallet, I could've ordered pizza.
If only I drove faster, I would've made it to the event.
If only I studied harder, I would've passed my test.
If only my teacher liked chocolate, she would've accepted my gift.
If only all people were kind to each other, the world would be a better place.
If only people didn't judge straight away, the world would be a better place.