My own response, (which probably is a repeat of what others have said):
In my own experience, sudden, momentous experiences have not been the norm. Growing up in a Baptist church and going to a Baptist college, most people when sharing their testimony desperately try to pinpoint a specific time when “gettin’ saved” happened, because thats what they think is supposed to happen. However, most of them make it pretty clear, that they through much time and thought and life realized, I believe in this guy and I’m following him, I’m not sure when it really started, but here I am. I think thats the way it happens with most people. Certainly one can have an experience where they were faced with a choice, “do i really believe this or not?” or “should I make this public right now or not?” or “if I believe all of this, then i shouldn’t be doing ____,” and that kind of thing, but I think its something that happens within the context of a process.
John Piper said once, “A decision for Christ isn’t nearly as important as a life for Christ.” Even in the gospels, the disciples highly irrational decisions to follow Christ, but was that the actual salvation experience? It seems like it was a process for them too.
The New Testament seems to focus quite a bit more on where we are in the present rather than what experiences we’ve had in the past. Take the entirety of 1 John, for example.
The church I attended in college was a little light on teaching the gospel than it really should be, but the average new believer begins attending as a non-believer, begins to learn new things about Jesus and God, gets involved, begins to really follow Christ and then realizes “I guess I’m a Christian,” and gets baptized. The ones who do that rarely turn away, its the ones who begin “following Christ” based on an emotional experience who often go astray.