Why not take the at home course and find out for yourself? Without a strong mindfulness practice, the theoretical explanations serve little beyond entertainment for the mind.
It is of course all "memory" but the explanation is a bit deeper. What is happening here is that the same physical world appears differently to each of us based on our signature set of tanha (cravings)(*1). For a full understanding of the mechanics of bhava, one needs to get an idea of Dependent Co-arising mechanics DN 15, MN 9.
Roughly: What we call a person can be modeled as a self perpetuating chain reaction of the 5 aggregates(*2). As MN 109 says, when there is phassa (contact) three of the aggregates arise - sañña (perception), vedanā (feeling) , sankhara (intention). Also as MN 109 says, based on the craving, different perceptions, feelings and intentions arise.
- For a snake charmer - the perception could be "a thing to catch for the next show", feeling could be pleasant "exotic species so next show will be a hit" and the intention could be "planning to catch it before it vanishes".
- However for someone with traumatic childhood experience the perception could be "danger", feeling could be extremely "unpleasant", intention could be "chain reaction of thoughts and feelings" tantamount to panic.
- If one retains mindfulness during the contact a very different set of perceptions, feelings and intentions will arise, all leading to equanimity.
How does karma play a role in the above?
- The 2nd link of Dependent Co-arising (DN 15, MN 9) is the record of our all our karma - like a flash drive.
- AN 3.77 hints at the mechanics for the above 3 examples - how karma is strengthened (examples 1 & 2) or overridden (example 3).
- Every intention one sets create new karma. e.g. "next time i see a snake i will run from it" or "next time i see a snake I will be more mindful"
- Every time one acts on the intention, the "chain reaction" mentioned above increases in strength.
- Idea then is to act on the intentions with mindfulness.
BTW this is an excellent question. It points to the issue of dukkha (suffering), its causes, its cessation and path leading to its cessation.
(*1) The above is also the same reason why an alcoholic see the wooden cabinet as a source of alcohol, while the artisan sees the same cabinet as an example of art. And in the limit, the same reason why an Arahant is completely free of suffering in this very world.
(*2) MN 109 defines the aggregates, how they arise and how they are perceived.