Why do dragonflies appear to me at very important times in my life?

A dragonfly appeared (flying beside my car at 35 mph) right before I got a flat tire on a rural dirt road, whence a nice single 35 year old man (my age) stopped to help change the tire (turned out to be a bad 4 month-long relationship); there was a poster of a dragonfly on the ceiling of the room where I had surgery; my husband's brother & his wife have dragonfly towels; the street of a brand new home my husband & I wanted to buy was named "Dragon Fly Creek Ave." (we looked at the name of the street AFTER we decided to buy the house). Dragonflies appear to me at life-changing moments. What does this mean?