Sentence 1: I think about balls all the time. 
 Sentence 3: Once, a large ball got stuck in a tree 
 Sentence 4:  I took a small ball and used it to get the big ball down 
 Sentence 5:  I only throw the small balls at the trees, now 
 Option 1: I used to have no balls. 
 Option 2: I used to have small and large balls.