I'm another who had exactly the same experience. That one sentence did the entire country a massive favour (and is, sadly, no longer true)

The quality of the documentation with these early computers was also truly exceptional. I learned basic in a weekend.

To elaborate your point every ZX Spectrum came with a detailed manual from which you could learn Basic.

And in the back it had a ascii table with all the Z80 instruction codes - so once you had basic down you could try assembly!

The keyboard itself was almost the Spectrum's own manual, listing all the BASIC keywords - because to enter one of the keywords, you just typed the key with that label. That made programming possible for a preschooler.

More than just that; the block diagram and a lucid explantion of floating point mathematics that has lasted me for 40 years.