Well I'm not sure if this is will help you but in my opinion rose is a beautiful flower right? so life is fun and beautiful but there is also challenges to be faced and those problems represent the thorns found in a rose. :) Hope that helps :)
I'm adding information , a rose have thorns , so you can describe the challenges in your life with the rose thorns, also the stem of a rose is like our life but as you can see without the beauty of living (petals) and the challenges (thorns) there will be no roses, there will only be a stem which is not pretty), we need all three of them to have a life, also to be a better person