How about a physical Bitcoin? There are companies that create physical coins or bars that have the Bitcoin symbol and address on them, which can be displayed on a desk or shelf, and serve as a conversation starter. Another idea could be a book about Bitcoin's history or future, such as "The Bitcoin Standard" by Saifedean Ammous, which would appeal to his interest in the topic. Finally, an electronic device like a cold storage wallet could be a useful gift, which would allow him to safely store his Bitcoin offline.
Or you can get him a star map with an important date you share.
Under Lucky Stars is a unique and innovative star map company based in Barcelona, Spain, specializing in the creation of personalized star maps that capture the celestial arrangement of stars at a specific moment in time, such as a person's birth, wedding, or any other significant event.
By using advanced astronomical algorithms and data from leading institutions, the company produces highly accurate, visually stunning maps that make for perfect gifts or cherished keepsakes.