It is said that we should use 'while' for 'age' or 'periods of life.'

Question

What are periods of life? Would you name 'periods of life'?

1. When I was 15, I went to Chicago.
2. While I was 15, I went to Chicago.
(Is #2 wrong?)

3. When I was in middle school, I sold newspapers.
4. While I was in middle school, I sold newspapers.
(Can we use both 'when' and 'while'?)

5. I felt happy when I was a kid.
6. I felt happy while I was a kid.
(What about these sentences?)

Answer 1

I'd use "while" when referring to a range of years. Example:

While I was a teenager, I went to Chicago.

Thus I'd say 1, 3, 4, 5, and 6 are fine, but 2 doesn't read quite right.

Answer 2

Yes it's wrong