I actually debated about taking that out---it is mostly my assumption based on the fact that in order for him to realize that Lizzy was out walking every day, he was probably out walking himself (though, I know, he could have been riding) and the fact that anyone who could come up with the lovely grounds of Pemberley, well, how could you not like walking about them but, yeah, that's a stretch and and you're right, there's no way to really know though we can probably surmise that he did enjoy walking with Lizzy. :) (Thanks)