weneedtotalkaboutsherlock:

Sometimes a piece of paper or a photo falls off Sherlock’s “string wall” he does during cases, and so when he’s not there to put it back John would stand in front of it for like an hour trying to remember where that damned photo/post-it originally goes. 

He usually gets it wrong, but it’s fine because it makes Sherlock smile as he replaces it correctly without mentioning it.

On one memorable occasion John put it on a place Sherlock didn’t think of and therefore created a link that helps him solve the case instantly in his mind. Which leads to a great deal of excitation and forehead kisses, and John being called conductor of light, of course.