Not really a sidewalk, but effectively one. Walking down the main hallway in our office (not terribly long, maybe a hundred feet), one of the guys who works not too far from me was behind me, and I wasn't walking too fast (funny, I'd say I wasn't exactly slow either, probably ambling a bit at perhaps 2.0 mph, I've never really felt like speedwalking to my desk to sit for a couple hours). There's a point near the area we both work in where it jogs to the right and you can go around either side of a table, and the guy behind me actually sped up a bunch and cut me off on the other side of the table. Close enough in front of me to be rude about it, but he really needed to be in front of me. At that point we were maybe 25 feet from the area where we work. I almost laughed aloud.
It did make me wonder what it's like to be him. He always seems outwardly angry, never says 'hi' to anyone he doesn't know well, hardly ever smiles, etc. Now I wonder if he lives out his days getting pissed at everyone that walks too slow for his liking, kinda like how I sometimes feel when I'm driving and can't find a clear lane that wants to go the same speed as me. The anger I feel in that situation has had a profound impact on my approach to driving as I've grown older; I try much harder now to remember that I'm not actually in a big hurry and it rarely matters one bit how long it takes to drive somewhere. I changed my definition of 'winning' the driving game as getting to my destination without my blood pressure rising.