In my first Freshman year of college (University of Missouri, Kansas City), I attended a free magic show. The magic show, as it turns out, was sponsored by a local Christian group called Cornerstone. The magician showed us his illusions, and then let us know that there's no magic and that Jesus died for our sins. Afterward, there was a book table hawking a variety of books that exposed the falseness of fortune telling, UFOs, the Bermuda Triangle, etc. I met several guys at that show, who met me for lunch in the student union later.
I remember that at that lunch one of them told me that he was like Paul and I was like Timothy. I remember wondering who had made him Paul. Had I asked the question, no doubt I would have received instruction in the Letter to the Galatians, in which Paul asserts that he was made an apostle by Christ Jesus and by no human being (of course, Paul had to submit to Annanias in Damascus after his vision). I didn't ask this question because I had always been an amiable, passive young man. I was also friendly toward these folks because in high school, several friends of mine were involved in Youth for Christ.
Over a series of weeks, I attended Bible study on campus and in the "upper room" of the Craftsman-style home that housed a family and certain churchy activities. I handed out tracts once. And once, I attended services, singing scripture passages a capella directly from the Bible (in Catholicism, we call this the Liturgy of the Hours!). In one conversation, the original three members asked me if I could remember when I was saved. They said that if I did not remember that salvation event, I would never be certain about my salvation. I answered that I never remembered a time when I did not know the love of Jesus and the desire to follow Him. The elder mentionned that his wife had been raised Catholic and made the same claim.
Throughout this time, I never doubted the Christian faith that I received from the Catholic Church, and I continued to participate in Mass and pray as usual. I spoke freely with everybody in the group about my understanding of faith. Eventually, the elders talked with me and told me that it would be better if I didn't come anymore. I didn't protest - it was time to move on. Years later, I realize that most folks didn't know what the elders had done, and likely assumed that I had drifted away.
Why did I stay? Thinking about it now, it was nice to be with people that enjoyed speaking about Jesus and trying to understand the Christian life. At the Catholic Newman Center, for example, the dialogue homilies were more about discovering psychological insights. And later Catholic Bible studies took on a similar tone. Also, it strikes me as strange that Protestants and Catholics both follow Jesus but generally avoid each other.