The advantage, though, is a chance to pick a new secret. I don't have many secrets; a combination of a philosophical tendency towards transparency and too much laziness to maintain lies means that I'm usually keen (sometimes too keen) to be as frank as the situation allows. But a password (usually more like a phrase than a word) is a chance to have a secret from everybody, and simultaneously a chance to write something anonymously on a wall (or rather to be identified as the writer while the wall and the writing remain unseen). To scrawl the same declaration of unrequited love in the margin of one's rough book every day, to etch the same lyrics on to one's pencil-case, without ever running out of space or biro ink.
In the early days of a new password it feels as though everybody in the room must be able to see what I'm typing, as though I'm going to be caught with the spray-can in my hand. It's a blush spreading across the wall of my face, brick-red. After a while it becomes a worry-stone smoothed by the fretting of my fingers and the sweating of my palm; a token, a talisman. It's a key, turning in my fingers, opening up, letting me in.