I, too, was 14/15 in '75. The effect it had on me was, "Oh, that's gonna be interesting - another prophecy. Will it be as true as past prophecies, or as impossible to prove (e.g., Christ's presence)?"
I never believed. I felt bad for the people that were getting so psyched up for it, putting important life activities on hold. I felt bad for the people that felt disappointed.
I was very angry that the WTS didn't apologize for getting hopes up, but instead made things worse by explaining things away with the "Eve delay" thing - and then people got back in line again, though some with a glint of suspicion in their eyes.
I felt like I was one of the few people with my feet on the ground in a tide of zealotry - preach! Armageddon! Preach! Last Days! Preach!
Noting the pussyfooting around the issue in PUBLISHED material made me doubtful. Not believing in 1975, I didn't tell people that Armageddon was coming when out in field service. I did say, as I believed, that the world was in bad shape and that no one could fix it but God. Do householders give any credence to a teenage kid on their doorstep telling them about the end of the world?
And every time I was at the Hall there was this grand expectation that finally, it was going to happen.
The 1975 expectation didn't have much impact on my notions of God or the Bible; it was probably one of the big issues in forming my opinion that the WTS was les by a group of crafty, crazy old men, though.