Brought my expired USC student ID and still got €10 off at Rijksmuseum, Van Gogh, and Stedelijk. They rarely check expiration dates carefully. Even worked at smaller spots like Willet-Holthuysen Museum on Herengracht.

Under-26 discounts are everywhere too if you're no longer studying — Just ask for 'jongeren korting' at ticket counters. Saved me like €40 across three museum visits last week!