People get tired, this shouldn't be a great news to anyone. We suffer from exhaustion, which impacts ours productivity, mood and precision. Whenever we work long hours, exercise, don't sleep enough or it just happens to be one of those days, we don't perform as good as we theoretically could.

This mechanism is rather unique to biological, carbon based beings, the living creatures. Machines, especially as we know them today, usually do not exhibit this behaviour.

Digital devices usually don't care much for the amount of work done, how long they were off. Sure, there are overheating issues when too much currents start flowing, but it's rather different from humans; our exhaustion problem isn't solved by entering the freezer.

Back in ye good ole days, machine used to be more alive, at least if seen through the lens of this imperfection. Old engines used to need some warmup, and when they climbed mountains the carburettors quickly found it hard to breathe in high altitudes, suffering the same weakness as creatures that steered them. Even light bulbs used to get weaker and weaker, dimming if power was not sufficient, which was common due to unreliable grid.

Quite reasonably, modern, digital devices abandoned the imperfections which plague the creatures. Now the machine usually exists in one of the three states: perfect operation, not being powered, or capital failure. So called sleep occurs, some overheating underperformance, but beside rare exceptions, there are no weaknesses. Unlike the creatures, modern machine just works or it doesn't.

The evolutionary decision to forswear exhaustion sounds rather sensible; maybe some day even we humans will do without it. Should such disposition be seen as an essential component in passing the "creatureness" threshold? Or is it sufficient if to be able of susceptibility to exhaustion, to consider yourself a creature. After all, is this where we might end up one day?

Meet Altria. Altria is a very strong creature; can perform work all the time, very efficiently. From time to time, she get's a bad day though. When those happen, she very easily gets exhausted. This may stretch for a while, some days are better some are worse. She will be fine though, Altria will manage through and eventually returns to her usual, perfectly optimal performance.