@VileSheep
Argh, I hoped no one questioned that. It is a strange sentence after all...
Japanese and Engrish are like one of the worst nightmares.
The kiddo said シーリング which can either mean "ceiling" or "sealing".
I don't think you can get into (get absorbed into something/get addicted to something) ceilings, so I went for sealings as in the stamp seals in envelopes since the kiddo is holding a fountain pen and you can see feather pens and ink bottles in the table.
So he probably got into either wax stamps or just cool pen utensils