I'll start off by saying that I have never had a significant experience where I "felt" or "heard" the holy ghost. Looking back on my religious life, I remember times where I felt the spirit, or what I was lead to believe was the spirit, but never anything that I can relate to a solid experience.
One of the main reasons I decided to question the validity of the church was due to the fact that I began feeling the "spirit" at very random times. Growing up I came to associate "feeling the holy ghost" with what I call "the chills". It's a tingling feeling that goes up and down my spine and reaches my arms and legs, leaving goose-bumps all over. This feeling would come over me when I watched touching church videos such as The Easter Story or the old First Vision video.
I never put too much weight on it. I never "tested" the gospel because I "knew" it was true. How did I "know"? I don't know. I remember finishing the Book of Mormon during High School and I knelt down to pray and I felt "peaceful", thus I concluded that it was true.
I remember the time when I prayed fervently to know if the church was true and didn't feel anything. Then, I had a random thought that translated to "You already know". I already knew, so I didn't have to find out again. But wait... I had also been taught to pray often to know that it was true, to re-witness the truth again and again so that your testimony can grow. Well, that obviously wasn't going to work with me because I already knew and I didn't need to go over it again just to get no real answer. The logic in this thinking is driving me insane. Wait, I think I'm already there.
Another experience was when I was in the MTC. I had not felt the spirit for several days and it was starting to bother me. I wasn't sure what was going on. I went to my instructor, who diligently probed to find out if I wasn't worthy. I assured him that I had no sins that had been left unrepentant, and he instructed me to pray until it came. Well, I prayed at every opportunity and eventually I started to feel the spirit again. Its weird thinking about that experience now, because I think it tells me a lot about how naive I was, and still am, about religious experience in general. Also, how was I supposed to teach others how to feel the spirit if I couldn't feel the spirit myself? I was doomed.
Over the last several years I have noticed that I would feel the "holy ghost" in totally random settings... reading an article on the internet, listening to a popular song on the radio, thinking about my wife and kids. I Googled the topic and found that my way of feeling the holy ghost is typical. And not just typical of religious people, but of the human race in general. In fact, its normal to feel that way when your thinking of things that are important to you, especially when thinking about nostalgic things such as how important your wife and family are to you. So, if this were true, then where does that take me with relation to the truthfulness of the Book of Mormon and the church? Well, I guess that leaves me with nothing.