I have begun to be a friend to myself.

Where this comes from

Seneca passes this line on in a letter to Lucilius nearly 2,000 years ago. He found it in the writings of the philosopher Hecato, who asked himself what progress he had made and gave this answer. Seneca adds that a person who is a friend to himself is never alone.

How you could say it to a five-year-old

“That was hard. You’re not stupid, you’re learning. I’m on your side. Let’s say it together: I’m learning.”

Hecato, in Seneca’s Letters 6.7. We put these lines into plain English ourselves, staying close to the original and to public-domain translations.