How was Boo Radley a lonely man?

Boo Radley's childhood was hard for him because he hung out with the wrong group of kids and they cut up the town. He then was taken in by his dad who was a foot baptist, which means he lived by the bible. Boo was kept in his house for 15 years. Boo then stabbed his dad in the leg with scissors as he was walking by and his dad sent him to the basement of the courthouse which nearly killed him due to the mold. Then he was brought back home.