What if;

 Harry's mother had never died for him?

What if;

Harry had shaken Draco's hand at their first year?

What if;

Tris hadn't chosen Dauntless?

What if:

Peter hadn't felt the need to save Tris?

What if:

Rose had never gotten separated from 10?

What if;

the Doctor never had a sonic screwdriver?

What if;

Peeta had never fallen for Katniss?

What if;

Katniss's father had never died and she hadn't had to grow up hunting for her family?

What if;

Percabeth hadn't made it out of Tartarus? (THE THOUGHT IS SO HORRIBLE)

What if;

Grover had never found Percy?

Comment what would have happened!

Hint: Most of the answers are "They would have died."

Just lets us appreciate how many coincidences and lucky saves went into our Fandoms.