What does the cryptic crossword clue "Older fashion's restyled? That's idiocy (13)" mean?

The wordplay uses an anagram. anagram of OLDER + FASHION'S = FOOLHARDINESS The answer is FOOLHARDINESS.

Older fashion's restyled? That's idiocy (13)

Daily Mail Cryptic #17024 | 15 Across | 2023-02-01 flower