Before we discuss this let us look at what Yogananda says
The short season of life will be gone before you realize it. Reap the harvest of divine happyness that nothing can take away. It is not impossible; you have only made of yourself think it is impossible. The power of God is within you, so when your mind tells you a thing can’t be done,say to the thought, “Get out ! It can be done.” And it will be,if you make up your mind. Why waste your time on spurious pleasure ? Go to the very source. If you remain in that Happyness all the time, you will also be happy in the world; you will see that all disease and suffering are but short-lived nightmares of the body…
Sri Sri Paramahansa Yogananda.
The Divine Romance…P.447…
The important points -‘
1). Life is short
2) Joy is in discovering out true self or relation to God
3) iItcan be done quickly
4) Our thoughts make it a challenge
So the question in that case is a Guru needed or is it just a thought we created and now we are trapped?
Ultimately the world itself is a thought. A dream of our own folly.
But to break the dream, we need someone to wake us , someone who is awake.
Otherwise, we will think we are awake but Just continue in the dream trap.
So Yes, we need someone awake a Guru to help us realize that we trapped by our dream thought or thought dream. This dream is not the dream of sleep but the dream of being awake.