Being an athlete isn’t a societal norm
The meaning of the word 'ambling' as used in the passage is to WALK OR STROLL.
In the passage, the author is saying that, he finds it distasteful to strut before a small child who is walking or strolling in a relaxed manner.
The meaning of the word 'curtailed' as used in the passage is to BE DEPRIVED OF SOMETHING.
The author is saying in this line, that he is deprived of beauty.
Answer:
guessing that the theme is making others fell as though they are included, Jesse is wanting to help make the new kid feel welcome, and as though he is included in the group. its also a good way to help him make friends, so he isn't always alone.