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

A dragonfly appeared right before a chance meeting with a future boyfriend, there was a poster of a dragonfly on the ceiling during a surgery I had, my husband's brother and his wife have dragon fly towels, the street of a brand new home my husband and I wanted to buy was named "Dragon Fly Creek Avenue". Dragon Flies appear to me at life changing moments. What does this mean?