I keep repeating this idea, but I want to say it right:

We remember in wholes. Some fragment is identified as a member of a whole memory which comes back to mind as a whole out of memory. Within the remembered whole the details become available to us, almost deductively.

We recall feeling and mood associated with a memory. An event occurred in the past, and at that time we responded with feeling and mood. But our response itself is not in our memory, only the images and facts of the event — and among them is the fact of our response. But when we remember, if the quality of the remembrance is sufficient the memory calls to the same feelings, and the feelings are re-had.

We recollect in parts. We rummage through memory, and collect fragments hoping that if we gather enough of them we will remember the memory to which they all belong, and perhaps also recall the feeling and mood of the memory.

When a mood is recalled, or occurs in response to life, within that mood we sometimes reminisce. Our present mood resonates with our memories and moves us to recollect details of our lives at the time when the mood predominated.