Because it was too painful to think about how his marriage had fallen apart due to his wife's infidelity, russell decided that he was not going to remember anything about his marriage. russell is trying to use a form of motivated forgetting, to ease his pain.
suppression
repression
decay
inattentional blindness

Suppression

Explanation:Suppression is a psychological defence mechanism in which a person consciously decide get rid of unwanted or painful thoughts or infomation. This means choosing to not be aware of certain events or situations in our lives. This means we carry on with our lives and choose not to be haunted by those thoughts.

Russel is supressing the memory of his marriage because it's too painful so he would rather not think about it or remember it.

the telephone is the answer