2, different. The first kind of wind is the real wind, which cools the sun with its coolness; The second wind is a metaphor of homesickness, which, like air, means that homesickness can't stop.
3. It shows the lingering homesickness in my heart, and the last two sentences are about the content of homesickness, that is, indelible memories and feelings of youth and ignorance.
4. Small light refers to the hope in the heart. The small light at night awakens the lost self and illuminates the future.