You know the Oatmeal, right? I love all of his work, but I think this is his most important: http://theoatmeal.com/comics/believe. It’s tough for me to understand why anyone wouldn’t want to cultivate a rainbow brain, but sadly, that appears to be state of humankind right now.
I also find it is people like that who are very invested in controlling what you do, how you think, and how you live your life. Why? I have no clue. Why could she not just accept that she could control her happiness or her moods, but you cannot control your happiness nor your moods, and that you had differing physiologies?
I mean, how would that have hurt her exactly? Or does she just delight in being a mean person? Did writing a nasty letter bring her joy?