When I was 13, we were visiting friends in another country and stayed at this family's house for a few days.

One afternoon, all of us were hanging out in their living room, the adults were chatting, and I was just sitting there listening to the conversation because I had nothing better to do.
The lady takes out a bottle of lotion, puts some on her hands, BUT THEN, she does something I've never seen before: she pumps out more lotion and proceeds to spread it all over her forearms and elbows. My mind was blown! 

I was perfectly familiar with

-putting lotion on hands throughout the day (have had dry skin my entire life so carried hand cream in my bag wherever I went)

-applying lotion all over the body, including forearms, after a bath or shower, and 

-applying lotion to elbows at random points during the day (more on that later)

But the concept of casually putting lotion on hands+forearms+elbows when chilling with your guests in the afternoon was, for some reason, absolutely groundbreaking to me. (Laughing out loud as I'm typing this)

Since that day, every. single. time I've used hand cream/lotion on any part of my upper extremities, I've thought about that situation and how it opened my eyes to new possibilities lmao.

Somewhat related to this, there is another thing I'm reminded of at least a few times a week - it's not one specific memory but rather a theme from my childhood and teenage years.

My mom would often tell me my elbows were dirty and I needed to do a better job scrubbing them.
When I was younger, she would come in and do it for me since, I guess, she didn't believe I was trying as hard as I made it sound. As I got older, she stopped "helping" me but would make a comment whenever she noticed my elbows that were persistently brownish-grey, standing out in contrast to the pale skin on my arms. She would show me her elbows that were the same shade of beige as the rest of her body and say, "THIS is what clean elbows look like. Now look at yours! They look like you haven't washed them in months. This is very embarrassing, and not only for you, but also for me, because people will think I don't pay attention to my kid's hygiene". 
Sometimes, she would be really mean about it and make me cry. 

I scrubbed them as hard as I could, often leaving the skin red and swollen. This would make it extra dry, rough and flaky, and it would sometimes crack and bleed - hence the "familiar with applying lotion to elbows at random points during the day" part.

They were always like this, but she didn't realize it and kept thinking that, on some days, they were dirty, and on others, they were clean(er). 

The truth was, in the summertime, when it was hot and I was wearing short sleeves/no sleeves, my arms would tan, and it became less noticeable; plus the school was out, so I wasn't spending hours each day sitting at a desk with my arms bent and/or having my elbows pressed into the desk,
and in the wintertime, when the tan would fade and the contrast would become more obvious again, I wore long sleeves because it was cold, so she didn't see them very often.

I was already an adult when I learned that: 

-It is normal for skin to be darker in areas where there is more friction and pressure. To protect itself, the skin thickens, and the outer layer builds extra keratine which gives it a darker shade.

-Constant pressure creates persistent irritation and micro-inflammation, and the skin treats it as a chronic mild injury. This triggers an increase in melanin production to better "shield" the area.

-My elbows are sharper than average - something I've heard from my mom since I can remember. "Ouch, your elbows are so sharp!!" every time I leaned into her while pressing them into her thigh. Turned out they really are sharp compared to a lot of people. Sharper elbows = more skin inflammation = more melanin. 

-Over-scrubbing contributes to the inflammation and therefore the darkening of the skin, so my attempts to meet my mother's standard for the colour of her daughter's elbow skin were actually making it worse. 

I often think about this and feel so sad for the little girl who was made to feel dirty and self-conscious for no good reason at all. I'm now a grown-ass woman with very few hangups regarding my appearance, and I know that my slightly darker elbows are the result of, well, being alive, moving around, and my body adapting accordingly, AND I'm also aware that people don't care about strangers' elbows and most don't even notice - but man, when I catch someone glancing in their direction, I still get this wave of anxious urge to say something like, "hey I noticed you looking at my elbows and I just wanna let you know they're clean". 

I don't say it out loud, but in my mind, I'm thrown back into that helpless state of feeling gross and unable to do anything to fix it. 

Aside from my mother, no one has ever said anything to me about the colour of my elbows, but the embarrassment from the hundred of times I've heard her say my elbows looked dirty got engraved pretty deep it seems like.

 So fucking unnecessary.