So in the first line "When I taught you at 8 toride a bicycle" and the last line "Like ahandkerchief waving goodbye" These twolines are basically the start and finish of herchildhood, first learning to ride and at theend being able to ride alone.
Imagery
When you read the line "Like a handkerchiefwaving goodbye" you can picture two things 1.Her actual hair flapping behind her like ahandkerchief waving goodbye" or 2. You canlook at in a different way and see This like she issaying good bye and leaving her dad behind.
Structure
There isn't much white space so I guess theauthor wanted it to be quite fast and upbeat.
Words Choice
"When you grew smaller, more breakable withdistance" The Author means that when you getfurther away it will be easier to lose that person.
Symbols
Bicycle
"I kept waiting for thethud of your crash as I sprinted to catch up"And finally when you learn all you need toknow you leave your parents behind and goon and live your life "The hair flappingbehind you like a handkerchief sayinggoodbye"
Personal Connection to theme
All of us will go through this stage in life someearlier than others