I was 15 years old and my school friend was continually talking to me about Jesus, etc, etc, and I was taunting him about references to Satan and 666 etc. In the end I said that I would not believe unless something weird happened to me. In the early hours of the following morning I woke up 'blind' and felt the sensation of being pinned to my bed by the head and shoulders whilst I thrashed about trying to get free. The sensation lasted a few seconds. I looked at my clock and saw it was 6 minutes to 6, and I estimated a 6 second experience. It fair scared the crap out of me. I talked it over with my friend and he reckoned Satan was making an attempt upon me for whatever nefarious reasons he might have. That evening I committed myself to Christ motivated by fear.
In the subsequent years I discovered that my experience was probably attributable to sleep paralysis and I no longer believe in the existence of the Christian Satan. So looking back now, if the event was in anyway supernatural, I would interpret it as my Heavenly Father being at work and using my friend's and my own flawed beliefs as a vehicle to get my attention.