Life Lesson: Everything you do sets a precedent. Everything. There's no such thing as saying, "Well, I'll do this thing that I'm not really okay with just this one time because of extenuating circumstances, but I'll never do it again." Because when you do it that one time, people expect you to do it again.
Most of what we consider to be "good" first impressions are in fact bad first impressions because they are inaccurate first impressions. Letting someone think you're something you're not is bad. Letting someone think you'll do something that you actually won't do is bad. "Good" first impressions are mostly bad.
I learned that today when after three years of working at a company without the accommodations that I needed all along to work there, and I finally decided to put on my noise cancelling headphones because it's too fucking loud there, my coworker tells me that our department doesn't wear headphones and that my boss would tell me to take them off if she saw me. I explained that I wasn't listening to anything and they were just to cancel background noise because the noise level was unacceptable to me, and she looked dumbfounded. Like, she didn't understand what noise I was talking about. Now, I think I'm going to switch to earplugs instead of headphones next week because they work better and that way there should be no confusion about whether I'm listening to music or not, but I don't know how my boss will react because she didn't notice my headphones today. I don't know how people are going to react to my wearing earplugs and my coworker's response about not wearing headphones makes me nervous.
But the thing is, I NEEDED those earplugs when I started! I always needed them, for the whole three years I was there, and I should have demanded that from the start. I admire people who demand to be accommodated or else they'll walk away. I could never be that brave. By making a "good" first impression for three years, I led people to believe that the noise level was tolerable and that I could work without accommodations when I actually can't, and no one will ever believe that I needed the accommodation from the start because I went three years without it and I was still "productive."
I'm telling you - everything you do sets a precedent. Don't try to make good impressions because you won't get your needs accommodated in the end, you'll just win the fake affection of people who only like you when you fit into their mold of functionality.