Why I can use "packages" by don't import it in "imports folder"?

I try to add erasaur:meteor-lodash package in Meteor 1.3.
But I can use it in imports folder by don’t import it.

// imports
Template.myTmpl.onCreated(fuction(){
           console.log(_.isBoolean(true));
})

That’s because meteor packages still export globals for backwards compatibility with 1.2

Importing them is still just good practice at the moment

Oh, Thanks for your explain.