The saying : Life isn't a bed of roses.
My opinion : It is true indeed. There are many ups and downs as we sail through the journey of life. Even if it's a bed of roses, still there are thorns in it. We can't even sit, stand, walk or sleep peacefully on such a "bed". We have to be cautious of what's around us so that we won't get hurt. Literally speaking, by the sharp thorns, it might be minor injury but a pain will always be a pain.
Image : fwallpaper.net