- Stepping on a branch while hunting because of a fractal pattern in the nearby tree.
- Get drop-kicked by a puma because they spent too much time looking at the ground while trying not to break a branch while hunting.
- Getting distracted and missing their ability to ambush prey.
- Their spear breaking because of a lack of maintenance.
- Spending weeks trying to improve their spear and forgetting to eat/sleep/drink regularly.
- Poisoning themselves/another because they started glossing over the details while picking mushrooms.
Control over concentration has never been solely a modern day requirement.