ELI5: Explain Like I'm 5

For Want of a Nail

Let's pretend you're a little knight in a big castle, and you have to get ready for battle against some big bad guys. You need to make sure you have everything you need to be able to protect yourself and your kingdom. You have your sword and your shield, but there's one really tiny thing you forgot to check- the nails in your horseshoes!

Now, the horseshoes on your horse's feet help them gallop quickly and keep them safe from sharp objects on the ground. But without the nails, the horseshoes will fall off, and your horse won't be able to run as fast or as safely as they need to be in battle.

So, you start riding your horse into battle, but just as you get close to the big bad guys, one of your horseshoes falls off because there wasn't a nail to hold it in place. Now your horse is limping and can't run as fast, which means you end up getting caught by the bad guys and lose the battle.

All of this could have been avoided if you had just checked the nails in the horseshoes before you went into battle. One tiny thing, like a nail, can make a big difference in the outcome of a situation.