When I was in my early 20s I was very interested in self-development books. I've read dozens of them. Maybe more than hundred. In one of them I saw a sentence a

When I was in my early 20s I was very interested in self-development books. I've read dozens of them. Maybe more than hundred. In one of them I saw a sentence and it changed my life. Whenever I'm bored what I do, I don't work anymore or not productive I remember this sentence: Whatever you do, please complete it. Stick it in your mind; if you will not end up what you are doing now, it'll have no value. Just complete what you've started.