Betty Smith said this quote

In his business, he observed human nature and came to certain conclusions about it. The conclusions lacked wisdom and originality; in fact, they were tiresome. But they were important to McGarrity because he had figured them out for himself. In the first years of their marriage, he had tried to tell Mae about these conclusions, but all she said was, I can imagine. Sometimes she varied by saying, I can just imagine. Gradually then, because he could not share his inner self with her, he lost the power of being a husband to her, and she was unfaithful to him.