Have you ever had a problem keeping a secret? Especially if that secret involves good news. I have certain friends who can't keep a secret like this. They are sure to blurt it out to the wrong person at the wrong time.
There is a timing that is ideal for releasing information or moving forward with a project. Jesus understood the importance of timing. When He performed His first healing miracle He instructed the man he healed with leprosy to not tell anyone. Now that would be difficult - not to share being healed from leprosy with your friends who have known you and your condition. He could not keep the secret.
As a result, Jesus could no longer enter a town openly but stayed outside in lonely places. Yet the people still came to him from everywhere. Jesus desired to do more things in that city, but because the man could not keep quiet, He could not do so.