Most learning if not all, is regulated by risk and reward.
Almost every behaviour is either to gain pleasure or avoid pain.
It makes total sense from an evolutionary perspective and especially in an environment rich with distraction and opportunity to have a brain function capable of identifying what is important and worth paying attention to now and for future events of a similar nature.
What are the mechanisms for doing this?
We usually don’t consciously decide to make something a long term memory or habit but rather it seems to happen automatically. Sometimes in ways that we would prefer that it didn’t like in the case of getting a phobic response.
One of the mechanisms for helping us remember things of importance or enjoyment is the production of various neuro-chemicals in the brain that create a state of neuroplasticity. This being a type of reset or unlearning/relearning state where new brain connections are easier to make and strengthen.
Oxytocin and dopamine being two of the most widely studied.
This study shows that when an unexpected memory test was given 24hrs after an activity that has random rewards within it, that events or objects close to the reward are consolidated overnight and become memories capable of being recalled.
Those events or objects not close to a reward are left out of longer term memory and considered unimportant. In other words, the rewards created more of these beneficial pleasure type neuro-chemicals leading to enhanced memory transfer from short term to long term memory.
The interesting thing here is that the brain backtracks to previous events or objects before the reward and labels them as important and therefore processes them during sleep into longer term memory.
Assuming an ancestry of hunter gatherers this makes sense to be able to relocate an important find or location.
If the memory tests were given without a sleep cycle then the results did not show an increase in memory like after 24hrs, showing that memory consolidation is indeed done in lower brainwave states.
So if you want things to be remembered.., add in rewards.