My father was a motorcycle rider and I grew up in a country of mopeds. The distinction of the presence or lack of pedals was an important one. I suppose it might not be to most captcha writers or captcha clickers. (Captchors and captchees?) 

 Yes, you have to literally figure out what goes on in those captcha writers heads... How OCD are they??? 

 And you never get answers when completing them.  Did I get 2 images presented because I guessed wrong on the first, or because I was randomly selected to perform a second as part of a training sample. 

 Yes! So annoying!!