I am excited all the time, but still, after hours of sitting, every moment of which could be "the moment", and not seeing a deer, it gets frustrating and , yes, boring, unless something else fills the time. When birds and other critters are out and about it is easier to deal with. Dark to dark during the rut or bear hunting is the worst. My area is not the best and it is public, which has its own set of issues.
Even with the best of places, what gets normal for him may NOT be normal for me, but it could still get boring sitting, especially if all you are there about is that one deer and not "mother nature".