Did Einstein say "if you can't explain it simply you don't understand?

Einstein said something that helps us understand how important simple explanations are.

Imagine you have a toy box full of blocks, some big, some small. If someone asks you to explain what’s inside, and you say, “There are many shapes made from different kinds of materials,” that’s like explaining it in a complicated way. But if you just say, “It has blocks,” that’s much simpler.

Einstein believed that if you can’t explain something simply, then maybe you don’t really understand it yet, just like how you might not know exactly what “blocks” mean unless you see them or touch them.

Think of a cake. A baker could say, “It’s a sweet baked food made from flour, sugar, and eggs,” but if you’re 5, that sounds complicated. If they just say, “It’s a cake,” you instantly know what it is, like when your mom makes one for your birthday.

So Einstein was saying: Don’t be afraid to make things simple, because that helps others understand too!