Think of it as acquiring an addiction rather than "learning" something. Look for the most addictive component activity the subject involves, that can be repeated with minor variations and increasing complexity as rapidly as you can go.

In math for example, this is graded homework problems of increasing levels of difficulty. For programming, it might be little coding problems. For people management, it is running effective meetings.

No individual instance should take more than an hour on average, for a meaningful "hit."

Now do this activity repeatedly. "Learning" is merely a supporting activity required to keep the hits coming. You'll find that you are endlessly resourceful while pursuing the next hit, just like crack addicts can be quite clever in finding money to buy the next hit.

Some people are serial addicts and can learn one thing after another, learning many things very quickly. Others get addicted to just one thing. Others struggle with even one thing. For the last category, the problem is often patience until the first hit. Once you have your first hit, the addiction begins.