If the only teacher you have is your suffering, you will need a substantial dose of it for the ego to dissolve. But if the power of spiritual teaching is already at work, then a minor event can dissolve the ego.

You don't 'have' a life, you 'are' life. The One Life, the one consciousness that pervades the entire universe and takes temporary form to experience itself as a stone or blade of grass, as an animal, a person, a star or a galaxy.

You can only lose something that you have, but you cannot lose something that you are.

Is there a difference between happiness and inner peace? Yes. Happiness depends on conditions being perceived as positive; inner peace does not.

So far for humans it has been the case that ego develops and then humans are stuck with it for the rest of their lives.

This is why very often you find educated people in the media who look at spiritual books but they are so identified with their thought process, they don't get it. They write reviews or articles and they miss the whole point. They can't see the essence. It's not their fault; it's not them personally. It's the human condition and its mind-identified state. And intelligence in itself doesn't help. You can have two or three Ph.D.s; it doesn't get you any closer to spiritual realization. In fact, you might be more distant.

A teacher or teaching is not essential for spiritual awakening, but they save time.