Because Radley is much older than them, and Scout, Jim, and Dill find him interesting because of this.
Answer:
im confused... i know its a song but.....
The answer that you want is pride
There is an envelope marked with the instructions that it is not to be opened until the death or disappearance of Dr. Jekyll. This implies that Dr. Lanyon knew something secret, but was unwilling to reveal it at first. He waited until there was no more "hope" of Dr. Jekyll staying normal.
