It's easy to get lost between book shelves when you're shorter than them. Not that they seem like too terribly tall shelves, but he's a rather short person. Ironic that what he was actually looking for would be on one of the top shelves and he could neither locate a ladder nor a sales assistant.
"My kingdom for a horse... or anything else high enough to let me reach the shelf." He wasn't sure what it was about Westerners and heights, but they did have a tendency of putting things our of reach.