The three main obstacles to learning (from memory) most important first:
1. Words - not defined, misunderstood, unsuspected meaning.
Symptoms: brain fog following reading or hearing such a word or symbol. May feel stupid. In severe repeated cases, gives up subject.
Remedy: go back, locate the confusion, look up the definition, make the word yours, use it in examples.
Take-away: Certainty on a fundamental bit of understanding.
2. Going too fast - skipping steps
Symptom: grind, drudgery, lack of progress, dip.
Remedy: Learn to do simple bits, the basics, right, until comfortable, then add difficult bits gradually.
Take-away: Build your basics first, then build on your basics.
3. Theory alone - can't learn to bicycle with just a book.
Symptom: growing uncertainty or unease, no fun learning, goal seems to go fuzzy, why do it at all?
Remedy: Get your hands-on, grab the things you are about to learn.
Take-away: If you wish to learn cycling, remove the pedals first, put the saddle low and dandy horse it on level ground until it goes where you want, comfortably. For an airplane find an experienced flight instructor.
Dictionaries and encyclopedias are almost everywhere. Use them, the slow way is the faster way. Imagine what may happen to education when you take all three obstacles effectively out of the system.