There is a car commercial out now with a little girl who claims her father is an alien. There are a series of shots from the girl's perspective and we can see how she thinks that. One of the shots she says"he's an alien, just look at him..." and he clumps into and out of the shot all kitted out in cycling gear; spikey helmet, goggles, form fitting spandex with almost skeletal outlines in high vis stripes, and he really does look alien. Maybe the person staring at you was seeing the same thing...