I grew up with people having natural colored teeth. People with artificial teeth color were those with false teeth. I find myself gradually getting used to it, but initially it did look like these people had quite serious dental problems: a problem bad enough to require all their teeth be replaced by artificial dentures. This is not attractive.

I have the same reaction to perfectly straight teeth or teeth without canines. It looks like false teeth. Crooked teeth isn't a good look either, of course, but forcing out all natural variation just looks like someone's had a problem. Uncanny valley: like someone with a synthetic flesh on their artificial hand.

I don't like the super white teeth either. Every person I have known, on a personal level, who had very white teeth; had a mouth full of cavities, extensive bridge work, or a bunch of money wasted on veneers?

Good teeth don't have to look flashy?

I think teeth whitening is a bit like steroids or liposuction. It is mostly for people who have insecurities and/or lack discipline to get quick, visible results at the expense of their health. I'm adding health here because these procedures, although deemed safe, are certainly harmful in some way.

There is a natural yellowing from coffee, tea, smoking and aging that even disciplined hygeine doesn't combat. Whitening (via oxidation) is nothing like surgery, being a meager, inexpensive, 5x5 minute habit that has a pretty big impact on perceived health and grooming. The downside is some temporary damage to your enamel, but it's less than a single cleaning at the dentist. If anything, I'm wary of whitening toothpastes, which are ubiquitous and tend to work via abrasion.

In my experience, tattoos and piercings are very common in Germany and also in Switzerland. They are certainly no longer limited to certain groups of the population and very visible, especially now in the summer …

Germany is not quite Italy, but tracksuits in public are not common either. It is just a thing in certain subcultures. When I visited Ireland, I saw not a single child, who did not wear one.

What part of Ireland was that? I don't think I've seen that outside of more deprived urban communities.

It was in Dublin a few years ago '11 or '12, I think. To me it seemed to be like there was an age threshold at which people start to wear regular clothes.

To say something nice: People were extraordinary friendly and walked up to us from 20-30m (100 feet) away to help us when we looked even remotely disoriented :)

Well, it makes sense that it'd be Dublin. More than likely you were seeing people who live in more deprived parts of the city. I can't say I've seen many children around Dublin dressed like that, mainly teenagers and younger adults.

I hope you'd a good time while you were here! I recommend you see some other parts of the country. For instance, Cork and Galway are great cities.

Really, no visible tattoos or piercings in Switzerland? I think you may be going a tiny bit too far if you want to generalize that as an European thing. Any decently sized city in Germany will have certain parts of it or just places where you will see plenty of people with tattoos and piercings. It's no big deal and has been this way for years now.

On the other hand I have never seen the specific tracksuit+aviators combination you mention. In fact, while I have seen plenty of aviators in the wild (usually combined with jeans and t-shirt or maybe even a proper shirt), I don't think I have seen many tracksuits at all, much less Puma tracksuits. (I think if you wanna go for tracksuits you should definitely go for some authentic Adidas.) I mean, aviators are kind of a thing like, say, Chucks are a thing (you see them often enough to notice that quite a few people seem to wear the same sunglasses/shoes, but it's not as though a majority of people wears them) but tracksuits are not even that.

Or maybe we just travel in different subcultures. Germans living in Switzerland are probably quite unlike Germans living in Germany. And maybe we can generalize this even more: There can be quite a lot of diversity in different groups of people and our simplistic differentiation along nationalities is just not precise enough and our stereotypes fall short. I'm willing to bet that there are certain groups of people in Germany and Switzerland who are absolutely crazy about teeth whitening and for whom no shade of white can be white enough – both of us just don't know any of those people. And maybe it's not yet as popular here as in the US – but that's as it usually goes with these trends. I mean, the future is already here, it's just spread around unevenly – and the same is probably true for our teeth whitening future. (Or maybe we will leapfrog the trend and jump right beyond to the next trend of super-natural looking teeth-yellowing or something like that. Or maybe a competing trend will be adopted by different subcultures or something else altogether. I bet there are also plenty of people in the US who would never ever whiten their teeth.)

How common is it, really, in the US? I genuinely don't know.

On the one hand, I hear that medical (and thus presumably dental) insurance costs a fortune, and even then the "co-pay" means that many hesitate to seek treatment. I can't imagine that "my teeth aren't as white as I'd like" is something insurance companies like paying for (or rather, they don't like paying for anything, but something purely cosmetic seems easy to deny), so how are people affording this? is it just the wealthy? If I wander around poorer areas, will I start seeing ordinary teeth?

Teeth whitening is very cheap, you can buy teeth whiteners over the counter in the US, and most toothpastes you can buy in the store have whitening agents in them.

Those whiteners don't create the super-bright almost-blue color you get from the dentist.

Are you sure? The handful of times I've inquired to an acquaintance about freakishly white teeth, they've always said it was just because they took really good care of their teeth, didn't drink coffee or soda, used whitening toothpaste, and had good genes.

Are you talking about those that last just a couple of hours or different ones?

What treatment lasts a couple hours?

You can get very effective peroxide gel kits on EBay for under $20 USD that whiten for many months.

Dental insurance is pretty cheap in the US. Medical insurance varies a lot, but for most people it is also pretty cheap because their employer pays the majority of it.