Why does mr lamb leave his gate always open?

I reckon the reason is quite simple, really. Mr Lamb leaves his gate open because he wants people to come in. He isn't scared of anyone. The gate is always open because he is always open to people. He says everybody is welcome. He doesn't even mind if kids come for his apples. He just wants connection, not walls between him and the world.

The open gate is a big symbol, innit? It shows he doesn't want to shut anyone out. It’s his way of saying ‘come in, you are welcome here’ to anyone who passes. He is not hiding from the world and he wants to welcome everyone in. He is lonely and he likes the company.