hooked on phonics

It sounds like the sentence is referring to Hooked on Phonics, which is the name of a specific commercial product. Hooked on Phonics is a set of educational materials that are designed to help youngsters learn how to read.

....and if you're referring to Slappy Do Do's signature line - he's hooked
on phonics for different reason

"Hooked on Phonics" ran a LOT of commercials in the mid to late 1980's during children's programming, and has thus entered popular culture. The sentence you quote is likely one of those ironic 80's pop-culture references that are frequently made by people who are now in their 30's or so.

Thank you very much, everybody.

I think I understand now.