Consulting the Codex…
RS3 · Skills · Activities · Quests
The Codex keeps its readings for 400 days, so you can go back that far, to the first day it read Weet-Bix.
Every common prerequisite the site could check is met for Weet-Bix. Gear, abilities, perks and relics decide the rest. Quests need a public profile, so the quest checks are left out of the score.