You'll Feel Right as Rain

The name of the achievement comes from The Matrix. There is the tail end of an exposition where the Oracle (Gloria Foster) offers Neo (Ted Theodore Logan Johnny Mneumonic Keanu Reeves) a chocolate chip cookie and says:

Here, take a cookie. I promise by the time you're done eating it, you'll feel right as rain.

My favorite quote by her, however, still remains the one right after Neo apologizes for breaking her vase:

Ohh, what's really going to bake your noodle later on is, would you still have broken it if I hadn't said anything?

This means eating 91 [item=62680]s (edit: by now also stated by the Criteria text) since the first one makes you feel 100% better, but any subsequent cookie will only increase that by 10%
Interestingly, this is not the maximum amount of "feeling better" you can gain (guess they wanted a round number for this achievement) but instead you can stack it 250 times to feel 2590% better.

If my sixth birthday party was any indication, massive vomiting.