I don't know how often people typically change their outfits in Belgium, but in the US people usually change their clothes daily. The US as a culture is obsessed with personal hygiene in a way that would make your average American appear OCD to people of other nations. So, yes, wearing the same outfit 4 days in a row is highly unusual here, and would typically be noticed by someone's parents on the second day. BTW, just to clarify, my explanation here is based on the assumption that you're confused because it's not unusual where you're from for people to wear the same outfit several days in a row, as I've heard is the norm in many places. Sorry if I'm way off base here.

Another Belgian here, changing your outfit every day seems pretty unusual to me. I didn't even know that was a thing in the US, you guys must spend a lot of time doing laundry!

American here, I had no idea people in other developed countries did not change their clothes every day. I actually thought #36 was being condescending because it appeared to me she was saying that people in other countries don't tend to their own basic needs like Americans do, and I thought it came off elitist. Turns out #36 was actually being very diplomatic and it's my own ignorant head that made assumptions. Carry on, then!

Yeah, my high school French teacher told me that people used to pick on her for wearing different clothes every day until she changed her habits. Yes, we Americans do a lot of laundry, or own a lot of clothes... or just alternate wearing the same unwashed clothes... not that I know anyone who does that... I think it must be one of those things that used to be a status symbol, but then stopped being a status symbol when clothes got cheaper, washing machines were invented, and the standard of living went up and enough people started emulating it that it just became the norm. It is silly if you think about it, though. Your clothes aren't dirty after just one day unless you sweat a lot or soil them. You really only need to change your underwear and your socks daily to keep good hygiene.

In the US it's very unusual for a person to wear the same outfit two days in a row, let alone four, and most people usually notice right away when someone they see every day wears the same outfit the next day.

Weird. Consumerism gone crazy. In my country no one would blink if you wear the same outfit two days in a row at work/school. If you wear it more than that, then yes, people would notice, and the shallow, douchy ones might make snarky comments behind your back. But again, I'm talking about school and work here, not about home. At home, it is perfectly normal to always hang out in the same old sweatshirt (well, until it gets dirty and needs washing, but still).