Since you asked.
So I was on the trip with the people (only one of which I knew prior to the trip, and even he I very barely knew). There were 29 of us, and me being me, at the beginning I never spoke much unless spoken to first (a terrible way to go about things, I'm well aware). On the trip, there was another guy named Sam who was much more outgoing than I; he was someone who got attention, and deservedly so. But it was unfortunate for me, because any time I would hear someone say "hey Sam" or something to the like, I'd be like "oh someone's talkin--nope." So for the first few days of the trip, I felt pretty shitty.
The third night, the place we were staying at had a bunch of rooms for us to sleep in. I found a room for myself and I started writing in a journal. To be honest, I don't remember what prompted me to do this. Around that time, one of my best friends and my college roommate at the time texted me asking how the trip was going, and I told him how it was going. Anyway, so with the journal, it was nice to just get some of the stuff out, y'know. It was like a release. Plus I could go back and read it and realize how dumb it was for me to feel the ways that I was (not like a "gosh Sam you're dumb" kind of way, but more like a "I can be better than that" kind of way). After a while, I leave the room and some people were talking about me and I was thinking "neat-o, I'm acknowledged!" and they call me over: "Sam!" It was just nice timing because I was feeling especially shitty from earlier that day, and then that night I was talking to my friend, the journal had me feeling better, and then that. Plus it made those people easier for me to talk to the rest of that night.
It was the following night that I opened up to everyone during one of our activities (the activity was basically "everyone say something you regret or something you are not proud of; then after, we all shared something that was going well in our lives." So it wasn't just me opening up, but everyone. That made everyone else easier to talk to for the rest of the trip and it started to not suck so much.