Whether animals do think remains a subject work within the science community. It is more known that animals operate by instinct if such word alone refers to those animal behaviours outside the operation of mere instinct, such as some behaviours displayed by common animals like the dog.
To think like a goat is a metaphor for ruminating on concepts like the goat does in its feeding mode. The goat chews some of its food and stores them in one of its stomachs. Later on, it regurgitates the stored food to chew again before finally digesting.
Goats are ruminants; their digestive process includes regurgitating partially digested food and chewing it, called ruminating. It is from this chewing of partially digested feed that the word rumination is gotten.
If you come across a thought, concept, or perspective which differs from yours in many ways, do not completely reject it away especially when it silently registers something in your subconscious. Later on, regurgitate this thought and meditate on it to find something you may have missed or which your ego or your need to be right may have waved aside. If it is okay to throw away certain concepts after they have been considered, then throw them away. But if you find something to learn and incorporate into your body of ideas, then use it.
Those ideas which resonate with some of your ideas but which you shoved aside because they came from someone you don’t always agree with it, or from a source you don’t subscribe to, those ideas will remain in your subconscious mind waiting on you to regurgitate and ruminate on. Your subconscious mind can pick up an idea that aligns with yours when your conscious, rational mind is warring against it. Sometime later, these ideas will come to the surface for you to ruminate on and where they lead you on to will depend on whether you ruminate on them like the goat, or you shoved them back down there, for another time.