All he feels is paper thin. Like if a strong breeze blew, he would blow away, never to be seen again.
As he ascends the stairs to 221B, he doesn't understand how his steps make a sound. How can these stairs recognize his weight when he feels so empty? Don't they know that they will never taste the leather of Sherlock's soles again, never creak under his hurrying steps? As they groan beneath John's feet, it sounds like mourning. For whom? Do they know that John is nothing but clothes and skin?
The flat tastes the same, like there's a secret hidden away in the dust. It doesn't feel cold like John's insides, like John wants it to feel; it should not feel like it did before here, but it does. It is empty now, though, and far too quiet for him to hear anything but his own thoughts.
He will never come here again. John knows that as he strips himself of his coat and toes off his shoes and his snug socks. If this is the last time, he wants to feel the cool hardwood beneath his feet like he did that night Sherlock taught him how to dance for a case. He can almost hear the music from Sherlock's open door drifting into the sitting room as he sinks into his chair, like the swirling dust has captured those moments and is reenacting it before his faded eyes.
How the carpet can feel the same as it did all those months ago, as Sherlock held his hand and taught John how to guide him around the sitting room of which they spent so many nights in, is a mystery to him.
None of it makes sense. He feels like it will never make sense. The dust continues dancing in each breath he breathes, mocking him. Sherlock said Moriarty didn't leave anything behind, but John knows these specks of dust are his, laughing at John for believing in that beautiful, broken man.
When he leaves, he will take what little is his and nothing else. He doesn't want anything more than another miracle.