But suppose your dæmon settles in a shape you don't like?

Well, then, you're discontented, en't you? There's plenty of folk as'd like to have a lion as a dæmon and they end up with a poodle. And till they learn to be satisfied with what they are, they're going to be fretful about it. Waste of feeling, that is.

But it didn't seem to Lyra that she would ever grow up.

Even though you want to try to, never grow up

Get this in mind early: We never grow up.

I was wise enough never to grow up, while fooling people into believing I had.

All my life I used to wonder what I would become when I grew up. Then, about seven years ago, I realized that I was never going to grow up — that growing is an ever ongoing process.

She couldn't get any further at that point. The sky full of stars seemed dead and cold, everything in it the result of the mechanical, indifferent interactions of molecules and particles that would continue for the rest of time whether Lyra lived or died, whether human beings were conscious or unconscious: a vast silent empty indifference, all quite meaningless.
Reason had brought her to this state. She had exalted reason over every other faculty. The result had been - was now - the deepest unhappiness she had ever felt.

Never grow up...always down.

Very few people grow up

You don't grow up, you grow old.

He was a poet; and they are never exactly grown-up.

Lyra learns to her great cost that fantasy isn’t enough. She has been lying all her life, telling stories to people, making up fantasies, and suddenly she comes to a point where that’s not enough. All she can do is tell the truth. She tells the truth about her childhood, about the experiences she had in Oxford, and that is what saves her. True experience, not fantasy - reality, not lies - is what saves us in the end.

Lyra had to adjust to her new sense of her own story, and that couldn't be done in a day.

Don't try to make me grow up before my time…

Lyra had never seen such a sight, never heard such a bellow; it was like a mountain laughing.