Your brain doesn't have to do anything extra (额外的) to tell the truth. You think of what you want to say, and you say it. Lying 1 much more work.
Here's an 2 of what goes into a simple lie. Imagine you're late for class and the teacher asks 3 and you decide to lie. You now have to either came up with a story or remember the story you 4 as you were rushing to class. So you say, "I had to stop by the 5 and borrowed a book." Your teacher asks, "The book I recommended (推荐) last period?"
You must decide how to answer 6 . If you say yes, the teacher might ask you to show her the book. Or she might 7 you to read from it in class. If you say it is a 8 book, she might ask which book you've checked out. So you have to be ready with the 9 of another book and make sure it's a book the school library owns.
You give your 10 a ton of extra work! Why not just tell the truth? It's much easier.