My cousin was telling me the other day that she wanted to read up all the fields of knowledge, such as maths, physics, psychology, philosophy, history, sociology, etc.
I told her as follows:
Yes, you can certainly try to acquire such knowledge.
But, given the limited time we have in any lifetime, you will have to be born again and again to fulfill that desire.
Moreover, even if you do acquire 100% knowledge of any one such field of study in one lifetime, it still poses a few problems, such as:
(1) That field of study is still evolving with ongoing research, which means that you can only know the knowledge in that field as it exists today,
(2) After acquiring such 100% current knowledge, where is the guarantee that you will not be struck with Alzheimer’s or some such dementia within a short time, which makes you forget everything you have learnt,
(3) Where is the guarantee that you will carry across such knowledge you have acquired to your next birth,
(4) Since this world is mere names-and-forms, any knowledge you acquire about the world, through the fields of study you have mentioned, is actually ignorance because the world is merely an appearance and not real,
(5) Also, where is the guarantee that even if you acquire 100% knowledge in this very lifetime in all the fields you have mentioned, you will get complete peace and happiness.
So, I asked her to look up Mundaka Upanishad that answers the question, ‘What is that one thing knowing which one knows everything’.”
Know Thyself 