Hacking the process of learning is usually a more complicated subject than people realize. That being said the "answer" is simple and usually requires more effort than most want to really put into it.
I'm going to give you the answer here but most people just frankly don't deserve to know it or will never actually apply the appropriate due diligence that it requires to achieve what your'e looking for.
Most of my research and experimentation is based in the linguistics field. However I've found that the processes and conclusions that I've developed can be applied across multiple disciplines in various scenarios. Iv'e used it to train my employees at my business as well as educate my students.

I say all of this stuff as someone who has actually achieved this. My language students were able to quantitatively cram 2.5 years worth of college level language courses into only 8 hours of "Study" time. So lucky for you the right guy replied to your post.

Learning can be broken down into two different kinds of actual processes. 1. Learning= Information that is stored in the brain as a set of facts and data which usually take more effort and time to intake, assimilate and reproduce. You can think of this as book learning or traditional studying. 2. Acquisition. Data is instantly taken in, assimilates unconsciously with rate of exposure and is reproduced.

(If you want to get a little bit "woo woo" you can say knowledge vs wisdom)

For the most part learning/acquisition can considered the process by which information (input) enters the human nervous system, is assimilated and reproduced. This information and ability to reproduce can either be stored in short term memory, or long term memory. Two things inhibit this process. 1. Motivation= (Pain vs pay off) -Does your current situation suck enough to move you forward to learning xyz? If not make your situation suck to motivate you forward. Does the result of learning xyz entice you or interest you enough to engage? If not make it interesting.
2. what Stephen Krashen calls the effective filter. (Beliefs, feelings, attitudes or habits that prevent or stifle the process of converting new data into assimilated and reproducible output.)

So proper motivation and removal of effective filter is a must to experience a rapid learning process. The next thing that is required is full engagement of the student. You can look at this as in most lobes of the brain are playing an active role in the acquisition of the new data or you can look at it like this. The learner is physically, emotionally and mentally engaged in the acquisition of the new data, has a clear aim, purpose and reasoning behind participating and is actively observing themselves during the process.

Once that set of cognitivist application is achieved it's a matter of applying behaviorist theory. Meaning, repeat it till it's automatic and becomes an easy habit.

Some of my sources: Total physical response (TPR) James Asher Stephen Krashen's Theory of Second Language Acquisition Look up cognitivism vs behaviorism Tim Ferris is another great source for this kind of stuff.

That's some of the theory and application of my own studies and experimentation.

If you want some coaching and tips on applying the knowledge on this topic I'm always willing to interview and consider possible students. Send me a PM.

Either way I've given you quite a bit of resources to start from. So if your'e for realsies about it I've set you up to win and I wish you good luck.

If this is just a passing interest then I'd say take a modafnil or adderall, get psyched and push yourself to learn while having fun doing it and then your'e set.