Eye protection, such as goggles, keeps bugs and dirt out of your eyes, which also has safety implications. Shoes are so darned practical that they can't be ignored either. Beyond that, there's a whole world of dazzling clothes that can help make you a more efficient, more comfortable, and safer rider. There can be a lot of wind out there in the world. Loose-fitting clothing flaps around, makes lots of noise, traps a lot of air, and makes you feel clammy from the perspiration.
Shirts can ride up in the back.
There usually aren't enough pockets in the right places. Drab colors may have looked more normal to a conservative eye, but they don't do a thing for visibility in traffic. So, for city riding, consider bright clothes. For cutting through wind, look at reasonably tight jerseys with high-tech fabrics for comfort. There's a lot to pick from.