After building a peg-chain story, how do you check you memorized the number correctly?

Decode it back: replay the story, read each peg's consonant sounds, and write the digits — they must match the original.

Encoding and decoding are inverse operations, which gives you a built-in self-test:

1. Recall the scene in order.
2. For each image, name its coded consonant sounds (ignore vowels and h/w/y).
3. Map sounds → digits and read off the number.

If the decoded number matches the source, the memory is sound. If a digit is off, usually a peg was fuzzy (e.g. you pictured "moon" = 32 but needed "mule" = 35) — sharpen that one image. This round-trip check is the discipline that makes the method trustworthy for real numbers.