In Guardians of the Galaxy 2, there is that famous scene where Yondu and Rocket try to tell Groot what Yondu's Fin look like and for him to go get it.
The point of all this is for Yondu to be able to control his arrow and get them out of the cell. But later in the movie Yondu tells Peter:
I don't use my head to fly the arrow boy, I use my heart.
So what was the point of him needing the fin in the previous scene?
My guess is that he needs the fin to control the arrow better or something like that.