Learn English – what’s a word/phrase that describes unwillingness to share advice (such as strategy on how to improve in a sports match)

Technically, it would be engram:

A physical alteration thought to occur in living neural tissue in response to stimuli, posited as an explanation for memory.

A better explanation:

Associative retrieval is an automatic reminding process. It occurs when a cue automatically triggers an experience of remembering. Strategic retrieval is a slow deliberate search of memory to generate hints and cures. Strategic retrieval interrogates the automatic retrieval process.

Encoding the experience strengthen the connections between groups of neurons. The resulting transient or enduring changes in our brains are called engrams. The engram is the representation of a memory in the brain. A retrieval cue induces a pattern of activity: if this pattern is similar to a previously encoded pattern you remember the event.

Non-technically, it would be reminiscence:

• an event that brings to mind a similar, former event.
• an event, phenomenon, or experience that reminds one of something else.
• the act or process of recalling the past.
• a mental impression retained and recalled from the past.

I can imagine: someone who tells you a story is the narrator ; someone who tells you information is an informant; someone who says things to a group may be the speaker; someone who tells you the development of a play or opera may be the moritatensinger; but I cannot find a unique word that includes all these. The person being talked at is the listener, the audience, the hearer.