What does Atlas tell Josh when Josh does not know if he should connect with his dad or not?

As Atlas and Josh sit in front of Josh's father's house, Josh is not sure what to do. Atlas tells him that his own father never sent child support or made any effort to contact Atlas. His father could have easily done a Google search and found him. Tim is a grownup. If he cared about anything other than himself, he could have found Josh. He knows Josh's name, the city he lives in, and how old he is. Atlas is surprised that Tim has Josh for a son and does not want to be in his life. Atlas tells Josh that knowing him is a privilege and that if he had known Josh existed, he would have done everything he could to find him.