My niece is kind of like your friend. In her case, she met a BAC and "fell in love". Now I call her "Puppet" because she just does whatever he wants her to. When they dunked her head in the water, they totally "brainwashed" her. :-P
By far, the largest group I have run into came to it as a way out of a debilitating addiction. However, it appeared to me that this was only a mild improvement and evidence that the underlying tendencies that led to their addiction were not actually altered by their religious conversion.
Born again as referring to being saved is the act of letting Jesus into your heart. Basically the believe that you can invite Jesus as coming into your life and from then on the Holy Spirit guides you through your life. This is where the term born again comes from, as in being a better person.
*cough* Load of crap. *cough*
That was putting it simply, to go into more detail it would take splitting the different diversities on Christianity. Even me saying the Holy Spirit directs them isn't true for all, only most.