What mistake did pony boy make in the beginning of the book? the outsiders

When Pony is coming back from the movies, he realizes he is alone. His first mistake is that he didn't stop to wait for Darry, Sodapop, or one of the gang members to go with him to the movies. This results in him walking home alone, which in turn makes him easy bait. He then gets jumped by the Socs, all because he didn't wait for someone else to go with him.