What Am I? Riddles

I am worn to mark a successful victory, I am also made of flowers and leaves formed into a circle, and I vary from big to tiny. What am I?

I am worthless, yet when added to others I add worth. I confounded the ancient Greeks, yet I changed men’s understanding. What am I?

I am wrapped but I am not a gift, I am kept neatly in a chamber and Archeologists find me as a great treasure. What am I?

I am yellow on the outside, white inside, and very appealing. What am I?

I am young in the sun and trapped to be aged. Held in a bottle but opening is delayed. What am I?

I am yours only once a year, you still cut me up with no fear. What am I?

I appear once in summer and twice in autumn, but never in winter. What am I?

I ask no questions but receive a lot of answers. What am I?

I beam, I shine, I sparkle white. I’ll brighten the day with a single light. I’ll charm and enchant all. I’ll bring the best in you all. What am I?

I begin and have no end. Eventually I will be the ending of all that has begun. What am I?

I begin your sentences. What am I?

I belong to everyone. Sometimes make you happy, sometimes make you sad. I will never end until the day you do. What am I?

I belong to you but others use me more often than you do. What am I?

I build up castles. I tear down mountains. I make some men blind, I help others to see. What am I?