It's not boredom, it's that we can go on forever without overheating. We have removable insulation*, our skin is made for sweating, we can carry a skein or gourd of even more water. While every other animal is panting its brains out, we're barely getting started on marathoning them to death.

* lol we skinned it from you, animals

You make some good points. That fact does have merit as many animals who do run fast and, as far as possible, do get a bit overheated. However, there are environments that we fare worse, such as colder climates where this sweating is a huge detriment and slows our progression towards the animals. Thus our capabilities to be able to do a boring task, such as watching prey, for long periods of time to strategies a good attack and make use of tools that are complex enough for an animals attention span and motivation to dwindle compared to someone who is capable of preservering to learn and create.

Life is complex and there are many reason that stem from the most simple facts.