At least there is something comforting about this question. It's everyone's business. Not just me or you.
Yes, why do we stumble over expectations, ideas and needs? Because at some point we learnt to differentiate. As a baby from me to my mother, as a child from me to the other child. For example, "I am the quiet one", "the other one is the noisy one". Or later on, I'm the quick learner, others are more difficult to understand...
So it's about developing ego identity, which definitely has advantages, but also major disadvantages. Chögyam Trungpa once formulated the cause of this development as follows: when we began to dance slowly and gently in the universe, we kept on dancing and suddenly realised that an ego was dancing. I am dancing. Instead of "dance-universe-star-movement-floating".
How do we get out of the confusion: through a "clear view", i.e. a direct view into our true nature, which is without confusion. This training is not training at all, but simply resting in the mind. James Low describes this impressively in his books and on his YouTube channel, and of course our path starts with Tilda Swinton's succinct and crisp insight: "I'm not a big believer in identity".