> Memorizing famous speeches probably isn’t much easier if you understand the historical context.

Not commenting on the merits of critical thinking vs memorization either way, but I think it would be meaningfully easier to memorize famous speeches if you understand the historical context.

For memorizing a speech word-for-word, I don't think so. Knowing the years of the signing of the Declaration of Independence and the Gettysburg Address aren't gonna help you nail the exact wording of the first sentence.

Right, isn't building up a (imaginary) context how people memorize pi?