The dictionary definition1 of philosophy makes it sound like a synonym for science. The etymology is more useful, it's just greek for the love of knowing. But we have geek/nerd to fill that slot now. My definition is the act of trying to answer questions for which we have no way of knowing if we have the right answer or not. It's distinct from science only in that an answer moves from philosophy to science when the answer is proven by experiment. It's distinct from religion in that philosophy becomes religion when it finds a form that the common man can comprehend. Religions are the memes philosophers emit while trying the answer the question, "what's the meaning of life?"
Before the scientific technique was invented, pretty much all questions seemed to have subjective answers so philosophy had a very broad scope. But science has now expanded so far philosophy isn't left with very many questions to answer. The most interesting of which are claimed by religion which is probably why I've found it hard to understand what philosophy is now. But it very much still exists. It's just very far from any day to day questions. In the physical world it's relegated to the trickier parts of quantum physics and the emergent properties of evolved systems.
We are all philosophers without knowing it since none of us are smart enough or patient enough to learn the scientific answer to every question. We take shortcuts, and these shortcuts in practice cause us to behave as if we subscribe to different philosophies. When interacting with someone equiped with significantly less intelligence than yourself you can't just subtract aspects of your world view in order to arrive at theirs. You need to subtract and then generate a practical philosophy for how the world works based on the lower capacity you're trying to emulate. This is why it's so hard to have a long term relationship with anyone that has a significantly lower intelligence level than you. It just takes a lot of effort to generate that philosophy2. Realistically it's going to take more than just effort. You would need to actually live with the simpler world model for a while to realise what sort of problems these people encounter.
"The study of the fundamental nature of knowledge, reality, and existence, especially when considered as an academic discipline"
And not the rewarding kind of effort either. Their world view is probably fraught with dangers that are obvious to you. But these dangers are unknowables from their perspective. You will probably be tempted to try and help the less intelligent person understand a slightly more sophisticated world view. But this will only work if the intelligence difference is small. The most likely outcome of all this effort is that you will become frustrated and they will think you a stubborn know it all or something similar.