He just had to try it.

During one of those boring and uneventful days at 221B, Sherlock encounters an interesting 'article' online.

"NEED A BED MATE? CLICK HERE" and "SLEEP BETTER WITH A PARTNER TONIGHT!" – All flashy red words with pictures of women in extremely little clothing.

"Boring," Sherlock muttered. "How can having a bed mate possibly make one sleep better?" he spat out to himself. "I find myself taking a kip on the sofa and I sleep just fine. John sleeps fine in his room as well.. Except maybe for the usual nightmare here and there. Impossible. The presence of another human being mustn't be enough to allow one to sleep peacefully."

After his little conversation to himself, he thought he would see the last of this thought. He cannot hide it away, however. He has predicted – rather, thought of – a hypothesis and, as a scientist, should see that all the necessary experiments are done.