What is a guaranteed way to learn algebra?

My answer to a question on Quora: What is a guaranteed way to learn algebra?

The question appears to be not particularly well posed: to learn algebra at what level? School? Undergraduate? Graduate? Research level? Starting from what kind of mathematical background? And what does it mean “guaranteed”? This expression refers to some level of expected outcome, to some criterion. For passing an examination? If so, what kind of examination? For further study of mathematics? If so – where, what kind of mathematics, at what level? For writing and publishing, in serious peer refereed journals, research papers on mathematics? For proving the Jacobian conjecture?

In my humble opinion, with all this variety of possible scenarios, in many of them there are well-tested efficient ways to learn algebra, but, to the best on my knowledge, in none of the scenarios there is a guaranteed way to learn.