Think of things like Idyllic Tutor or Three Dreams, both tutors for specific card types that are over costed and way too narrow to have any sort of competitive Constructed impact
Oko comes down on turn three (often sooner, since green is the color of mana ramp), and if you don't have some way to dish out 6 damage right away, there's not much you can do to catch up
Gaining three life off a Revitalize might not seem to do much, but if you pair it with a Sanguine Bond, suddenly it looks more appealing
Thank you so much.
Phyrexian Vindicator is another White mythic rare, but this one costs four mana, has flying and is a 5/5
If you want to protect your new cards, you may want to pick up a pack of card sleeves, which are likely available at any store that hosts a Prerelease event