You probably got here by accident, it is easily done. I’ve done it myself. There’s a loose tread on the staircase. One minute you’re stepping through a puzzle in your mind and before you know what happened you find yourself wrong end up in a dark corner full of cobwebs half buried under a toppled stack of discarded books.
No harm will come of it, just turn round and leave the shadows quietly, no-one will ever know you were here. When you sleep, you will forget yourself and all will be as once it was.
Arnica is good for the bruises, but you won’t remember that any more than you’ll know where they came from.