I've been a Catholic for 76 years, Catholic schools and all, and I not have never taken that "oath", I've never heard of it.....where did you see it?????
Well, God Bless you. Here’s the website.
http://www.catholicplanet.com/infallible/promise.htm
And also, here’s a link to the Catechism, which I’m sure- you like me- had pounded into you by the Nuns.