Did you know ...
... the olive tree is one of the oldest known symbols for eternal life. It is evergreen, can become at least 4000 years old (maybe more), and if it's burned by bushfire and seems completely dead after some years it can open shoot again. Oil from the fruits was used for lamps, giving light, body and hair care, giving beauty, and for meals, giving nutriment - so by this times covering a broad range of human needs.
In ancient greece an olive branch was handed over not only to athletes of the olympic games but on many occations. A symbol of showing respect or reverence. The meaning of this was roundabout: "May be peace with you, may you live forever."
There is a well known variation of this symbol also in the Holy Bible, when a dove brings an olive branch to Noah as a sign from God with a similar meaning. "You made it through deluge, may you find peace and a blessed life from now on." According to the Bible Noah became more than 950 years old.
In modern times the (white) dove took over the meaning of peace, which isn't entirely correct as the dove (until peace-movement messed it up) represented the spirit, the soul - in case of the Bible, the holy spirit. You may have seen on festivities, they open cages and let hundreds of doves fly up in the sky. Now you may alread guess what the meaning of this is: to set the spirit free (deliberate it from boundaries).