Paying close attention to his conversation with Rocket, you can see a bit more of the age and wisdom in his person, particularly due to the fact that Chris Hemsworth seems to have adopted more of the tone and mannerisms of Anthony Hopkins’ Odin.
We’ve seen the son become the father, and now he is ready to become the hero he was always meant to be.
The quest itself is Thor’s way of trying to build himself back up after the most devastating losses, and Hemsworth is most certainly game for that.
After losing everything, Thor is severely desperate to get back in the saddle and be a hero again, only this time it’s not out of youthful impulse.