Overfitting is bad for humans too
The study conducted by Angelo Maravita and Atsushi Iriki in 2004 talks about how an external object can become an extension of ourselves when the object is a part of the daily tasks that we perform. This is observed across animals as well as human beings. Examples highlighted in the research are things like a rake which the monkeys use to reach somewhere. The same can be said for a pen a writer uses to express his/her thoughts on paper.
So, the particular conclusion that researchers arrived at was that the external object is baked into the neural networks governing the brain which incorporate this extension to the body as being one with the body itself.
This has both advantages and disadvantages. The main advantage, which is quite obvious, is that it allows humans and animals to survive and accomplish frequent tasks with ease, almost without any effort. But the main disadvantage, which is analogous to the idea of overfitting in a neural network, is the fixation that one is prone to when using such an object in their daily lives. The fact that one is able to depend on something to get stuff done might give extreme regard to the very specific thing itself, rather than the idea. So, one cautionary tale arising from this is that one should incorporate a very flow-like mindset, where given any jar, one can fit their knowledge into it, but at the same time there is no memory of the jar being maintained so that the knowledge is free from any sorts of bounds.