Is this true for a majority of people? If so, how is it that the other person in my interactions enjoys it? Even when they care far less for me than I do them? To me, it appears all that's necessary is touching the right body parts. I guess that's what confuses me the most…the guy always enjoys our interaction a lot while I couldn't feel a thing.

From my experience, yes it is true for most. If the mood isn't right or the woman doesn't feel comfortable, then achieving arousal is near impossible, no matter which body parts are being touched. Arousal is as much mental as it is physical. Now, erections are strange things, men wake up with them in the morning despite having zero invitation, so they can be a tricky source of data at times. When boys go through puberty they have many unwanted erections, and while that may certainly point to arousal, trust me when I say its not always enjoyable. Especially not while you're talking to your teacher or apparantly minding your own business. Its awkward to hide, and from what I've heard does become uncomfortable and even painful Then there's this to factor in as well; I have guy friends who say they've had sexual encounters and even full on sex, but weren't even really turned on by the experience despite having an erection. They had an erection and followed through because the opportunity arose... They weren't at all into it.

That makes sense, but I don't really see how that would ever be possible for me, now that several experiences in a row have been disappointing and possibly even disturbing.

I have no idea how to put myself in that situation again safely and without alcohol or anything like that.

You have a habit of speaking in absolutes and this counts against you in many ways as it has a defeatist ring to it. I'm far from the unicorns shyt rainbows camp, buttt, I'm open to possibilities. Like they say, only 2 things in life are certain. Death and taxes. The secret is to only put yourself in these positions when you feel safe with someone. That way you won't have to pour for courage and have all your sexual experiences intertwined with alcohol.

It is widely accepted that past behaviour is a strong indicator of future behaviour, but nowhere have I come across the widely accepted belief that past experiences are a strong indicator of future experiences... Rather we learn from our mistakes and make different choices in future so we can have better experiences.

My past bf was an abusive, selfish, drug addict, my current bf is the complete opposite. He's respectful, caring, kind and attentive...

So while I used my past experience as an indicator for what NOT to look for in a partner, I didn't condemn all men or future experiences because I've had a string of bad experiences in the past...

Its up to you whether you're going to be open to new and better experiences in future, don't let your past rob you of your future.
Hope that makes sense I should be asleep

I could have sworn I said no, but he continued to push me. I guess I wasn't adamant enough about it? Or I felt that it would just be better to get it over with so he would go away. I didn't feel like my no or any sort of no would be taken as an actual no, but as an "ask me again". What was I supposed to do when he asks to kiss me? Shouldn't any response but a clear yes be enough. I don't remember if I was literally able to say "no", but I had clearly checked out and had changed the subject. Also, I would think lack of eye contact would say something too.

Sometimes silence can be interpreted as "yes" or "maybe if you persuade me", or "I'm thinking about it" to some... I'm not saying its right, I'm just speaking from experience. But a clear "NO" is unquestionable. I've been in those shoes when a less than firm "no" is followed by some prompting or pushing... not cool, like why do I have to shout???
But, that's exactly why as a young teen girl I had already adopted a stern and clear "no"... it may even sound cold to some. Lack of eye contact is interpreted as shyness by many, so that's not a very good "no indicator" and I strongly recommend NOT using it.

And at what point do I stop them? It seems common to think that if they're allowed to touch you at all (like even put their arm around you), then you're signed up for a whole bunch more automatically. But if I refused to be touched at all, doesn't that make me seem crazy and unreasonable?