I have even better - I3P. Iodine, check. No goiters here. 3, widely believed to be the next highest whole number (citation needed). Phosphorus, check. Good for flower/fruit production.
Put it all together, you might get grapefruit sized growths, but they won’t be goiters.
Next problem please.
You seem to be pointing out that formal education isn’t needed to learn something. That’s obviously true. The person you’re responding to seems to be saying that being a librarian is a job that requires a nontrivial amount of learning. That learning is on the level of something like a masters degree. This is also true