When you're Elliot's size or bigger, what you get used to is that when you come around a corner too close to people, some of them yelp and jump away. If you move too quickly, you see startled people's heads jerk around in alarm, and in a bad situation you may notice a police officer's hand reflexively dropping to his or her holster. You get used to coming down the street on foot and, if it's uncrowded, seeing people a block ahead crossing to avoid being on the same sidewalk as you.
The whole social-interaction thing is very much a series of mixed messages for very large men. A bunch of it is that the way most people interact with you is about your size, rather than being about anything else about you. Some people feel like they have something to prove by messing with you. Some people want to be your friend because your size makes them feel safe. A lot of people resent you because of your perceived 'privilege.' A few people are attracted to you on account of your size. More than a few tend to fall into a sort of de-sexualized child/adult interaction - possibly because your size may remind them of being children, possibly just because it places you in category 'unrelatable other,' as though you were a different species, and any kind of personal relationship is clearly impossible.
And finally there are a significant number of people who are just plain terrified of you, no matter what, because you remind them of someone who happened to them in the past - possibly when they were small children. That's not your fault and it's not theirs, and they may be ashamed of the fear and they may be trying to get over it and they may be trying to keep it secret and they may not, but there isn't jack you can do about it except you just try to move past them without causing any more pain.
Don't look at Elliot and think that his physique ought to fill him with confidence. That isn't how it's going to work. Most of the time it probably fills him with "well, I wonder how this next person's going to handle it...."
Which, in the end, isn't that different on a personal level from "wondering whether I can get along with this next person" so to some extent it's a universal experience. It's different, but being bigger doesn't make it particularly better.