I personally am always concerned about loose articles and have found lots in Club aeroplanes
I always have a very good poke around any aircraft also. Only the other day I found a French loaf underneath the pax/co pilots seat and I kid you not.
I seriously do not believe that someone's height perception is primarily derived from the perceived dimensions of the runway.
Neither do I. I've never bought the 'narrow/wide/short/long' argument. If you don't know what a thousand or five hundred foot above the ground looks like then it's time to hang up the flying boots.