Growing up, I always felt different from everyone else. And not necessarily in a good or bad way but just not the same. My life was very different from my peers but it wasn't just that. It was other intangible things that I couldn't define, if asked to do so, that made me different.
When my friends were going over to each others houses for parties and sleepovers, or to hang out at the mall, I was at home, taking care of my younger siblings. My Mom worked many hours and I was their main caretaker. My youngest still feels like my own (I was 17 when she was born). She often came to me first instead of my Mom whenever she needed anything. I don't regret any of this, it was just my life.
I was a sickly teen and ended up in the ER 2-3 times a year every year. I used to think that I would die before the age of 25. My asthma was really bad and the controllers they had back then were pills which caused severe side effects in me(large muscle cramps like my calves would cramp so bad that it hurt to walk/hands shaking so badly that I could barely hold a pen/rashes), so much that I couldn't take them regularly and had to depend solely on my rescue inhaler. When it failed, then the ER and nebulizer treatments and often epinephrine shots were what I had to look forward to. This also added to my feeling of isolation, like I was the only person like me in the entire world.
I think that feeling continued until I was in the US in college. I finally felt like I'd found kindred among my friends. I've always been outgoing and have had many people who call me their friends. Personally, many of them were/are merely acquaintances to me and few are what I'd call real friends. After college though, so few of them stayed in touch. I too am partly at fault for that. I tried with the ones I'd once felt so close to but they mostly pulled away from me. So in the town I pretty much call home, I made new friends. Some have drifted away from me, some I have drifted away from, and others have stuck. I like to think that it is the good ones that have stuck. Here and now, I feel less different that I did as a kid or a teen. Still different but not so much that it really matters anymore.