The correct answer?
I'm only found at the end
When you're looking for the answer to something, your search is over when you find it.
But never can you find all of me
There are an infinite amount of questions, you can't find answers to all of them.
I'm the smartest guy around
The correct answer is never wrong - I guess this would make it the smartest guy around (if it were a person)
I know as far as the eye can see
Answers are everywhere - This could also mean that there is an answer to the question: "How far can the eye see?"
Find me, and you'll sigh in relief
It's a relief to find the correct answer to a hard problem
But don't get cocky, your victory is brief
Even if a question is answered, there are still many left unanswered.
For I'm gone again, I am everywhere
Once you find an answer, you often set off searching for another. Answers are everywhere if you know how to find them.
It won't be long before you must find me again
We are faced with new questions that need answering every day
If I'm never found I wait to be discovered
If nobody finds an answer, it doesn't stop existing, it just waits to be found
You're looking for me right now, I'm just hidden and covered
We're looking for the answer to this riddle!