It's as good as it sounds....maybe even better!
Yes, you can learn without "trying".
It's called what I like to say is "atmospheric learning" or learning by "osmosis".
What is that you say?
It's about taking your "learning target" and applying it gently to your environment and putting it on a loop for as long as you wish, in order so that you will "absorb" the data casually as you are going about your daily activities.
So what does that look like? Well, let me give you a few specific examples.
Let's say you are trying to memorize the elements from the periodic table. You could, go to your favorite musical device, go to Youtube and find the best version of the "Periodic Table song"
press "play" and then put it on a loop ( to repeat over and over and over until manually cancelled.) You wouldn't have the volume too high. The idea is to have the data flowing continuously into your personal environment until your unconscious mind is so saturated with the information that you have "learned" it and perhaps even "mastered" it ......without even trying. You continue your regular activities like doing laundry or the dishes or cooking or cleaning all the while you are keeping the chosen data flowing into your environment. You will be listening intently even without trying. It is literally "natural learning"......and as easy as listening to the birds singing.
You can do similar things with other things you may want to memorize, such as scripture verses or classical poetry, or the multiplication tables.
We have so many hours in the day during which we do mundane activities. Well, we can pump up their impact on our lives by filling the ambient atmospheric sounds to include data that will become an asset to our lives and/or careers. Yes, it is that easy.
So how often will I need to listen to something before I have "naturally" memorized it? That's a personal thing, that will be uniquely different for each human being.
You can experiment and see how long it takes for you to incorporate one piece of new information merely by pressing "play" and keeping it on a loop. Will it take one hour, one day? or seven weeks of 20 hours per week? You won't know if this is a feasible learning style for you unless you try it.
May God bless your learning and the fulfillment of those goals that please Him.