...that it's often hard for me to gain entrance to a new book.
I keep trying to begin, and each night fall asleep only a few pages into it.
Then, the next night I forget what I had read and start over.
I picture it like running to get up enough speed to jump aboard a moving freight train; once safely on it I can just hang on and enjoy the ride.
But sometimes it takes a number of tries.
This is just a polite way of saying:
"I'm going to bed early, 'cuz I'd really like to jump on that train."