[ Lovecraftian Horrors (specifically Cthulhu, who he still doesn't know the name of) haunt his dreams and startles him awake every time he sleeps. Therefore, no sleeping is clearly the solution here since he can't stop himself from dreaming. ]

Most of my meals are prepared by someone else at home, and I lack easy access to a kitchen, unless I want to brave its queen and protector. Even if I learn here, those skills will be wasted once I return to my world.

[ Mrs. Hudson puts up with a lot from her troublesome tenant in his rooms, but she does not permit the same outside them. ... Given how Sherlock would put metal in a microwave for science, she has very good reason to ban him from the kitchen. ]

I suppose knowledge of how dishes are made could be of use in my profession if they connect to a poisoning, but knowledge of the poison often trumps that of the food itself.