Tulips?

Yep, they are a very Dutch export product. But they grow in a very small area of the country and the farmers take off the head before the flower really opens to force the plant to grow the important export product: the bulb, hidden under the ground. So we really don't see much tulips.

Wooden shoes?

Yep, in agricultural areas some people still use them regularly. When you're used to it, these clumsy looking things are easy to wear, light weight, perfect protection against wet feet, sweat, frozen toes in the winter and blisters in the summer. Mud, clay and manure don't stick to the surface. But most Dutch people don't live in rural area's and even most farmers nowadays prefer to wear ordinary boots, shoes, Nike's and such.

Traditional dress?

Yep, in some villages the pre-war generation still sticks to the traditional dress codes, each village has it's own characteristical clothes and jewelry, often the clothes also express things like nobility, social rank, occupations and such. The generations from after WW II hardly show any interest for these traditions, some do dress up in semi-traditional clothes for fancy fairs and the like, but with no eye for detail, you can see a maid in semi-nobility dress, a widow in bride's costume and so on.

Most of us prefer clothes like T-shirt and jeans, the fashion shops in Holland have about the same collections as in the US.

Windmills?

Yep, once there were thousands, most of them pumping up water, in several steps to higher canals, finally flowing into the sea. But windmills were also used for milling grain, sewing timber and so on. They became more or less obsolete by more reliable energy sources like coal, diesel, natural gas and so on.

All windmills stood more or less in the open and were mostly wooden structures, very vulnerable to lightning. Those windmills that still exist, several hundreds, are currently taken very well care of and even rebuilt when one is destroyed by fire. And their role in keeping our feet dry is in wet periods still fairly big.