Discretion is the better part of valor

I'm getting off to a wonderful start this year so far.

Since I was so busy and had almost no free time last year, I read books without making time for sleep, but I've stopped doing that. What’s more, I stopped caring about one of my friends. He just made me sick and tired of(Of what? of Him? of his complaining?). I learned through this tiresome situation that I sometimes have to harden my heart against people (In order) to protect myself. I think I should have been wiser early on.