There's something about the center of Warsaw that intrigues me. Between driving distance and walking distance, everything seems much closer than it actually is. I could blame urban planners for this, but I guess I like it.
One particular main street may give you the feeling that reaching the end of it is within walking distance. However, if someone's expecting you on that end, you should consider taking a bus, otherwise you will be late. It's longer than you think.
Walking around the city center, you'll feel you're lost in a huge maze of impressive buildings. But, then again, you can reach any point in under 3 minutes.
We all realize, sooner or later, that the perception of time depends on how much fun you have doing whatever it is you're doing. In Warsaw, distances also vary. Neat.