Answer:
Rex wants his children to be fearless, to stand on their own two feet.... in this case, to sink or swim. This is similar to the incident with the fire, as Jeannette is thrust by her parents into situations she is unprepared for.
Explanation:
https://www.gradesaver.com/the-glass-castle/q-and-a/a-how-does-the-following-passage-epitomize-the-walls-lifestyle-and-demonstrate-jeannettes-tolerant-and-understanding-character-how-does-the-swimming-event-compare-to-the-fire-incident-on-p-9-418908
https://pcteixeira.weebly.com/reflections-on-the-glass-castle/once-i-got-my-breath-back-i-figured-he-must-be-right-there-was-no-other-way-to-explain-itwalls-66
