Hi, I'd like to help you with your question.
It sounds like you may have OCD- Obsessive Compulsive Disorder.
Obsessions are repeating unwanted thoughts or fears that may be temporarily relieved by an action such as hand washing or counting. If the actions are not performed, then the anxiety associated with the reoccuring thoughts becomes worse.
Compulsive behavior is repetitive behavior that includes any action that is taken to relieve obsessive thoughts.
Your ability to recall conversations with others and to read behaviors can be attributed to good memory retention and/or your ability to focus well because of your attention to detail. It is very common to find that someone with an OCD is able to recall detail because they tend to be hypervigilent about their environment. Also, you are probably highly intelligent which adds to your ability to retain information and recall detail.
The cause of OCD is not known but it is thought to either be biological, genetic or environmental or possibly a combination. Onset is usually in childhood, adolescence or early adulthood.
Diagnosis can be done by a therapist or psychiatrist. Treatment includes individual therapy (cognitive behavioral therapy is a good option) and medications including tricyclic anti depressants and SSRI medications. Also, anti anxiety drugs such as Zoloft also help control the anxiety associated with intrusive thoughts. Also, support through therapy and self help such as support groups helps relieve symptoms and is helpful in managing the disorder.
I hope this has helped you,