Why pursue knowledge in view of all the difficulties associated with it? This is a good question. If we believe in Plato's account of Socrates, he even paid the ultimate price, namely with his life, as the Athenian government executed him for corrupting the youth and denying the gods. Notwithstanding these difficulties, there are many reasons why Socrates and many others seek knowledge. Let me name a few.
First, there is almost an inward impulse towards seeking knowledge. For Socrates, it was his tutelary spirit that prodded him towards knowledge at times. For many others, it simply is a desire to learn, perhaps even for the sake of knowledge. Many people will say that it is hardwired into human to learn.
Second, there is something gratifying about growing in knowledge. We can attest to this on a existential level, as we rejoice at graduations and other academic accomplishments.
Third, often the difficulties of obtaining knowledge is undertaken to move ahead in this world. Many people will suffer in this area to gain an advantage and to carve out a better life for themselves and their families.
I am sure that many other people will have more answers.