"A Clock" - Reasoning: Seeing the time on a clock can bring you relief, (e.g. your work shift nearly being over), a curse, (e.g. how long you still have left of a work shift), or simple clarification of what time it is. A clock is always running but always returns to where it began, to repeat. Thus, it is stuck in a loop. And as punching at work, appointments, taking to children to daycare, watching a film at the cinema, et cetera, all require you to be at a place at a certain time, time, which you read on a clock, does rule your life. The only exception is when you do not have a schedule to keep. And traditionally, clocks are usually placed on a wall, above eye level, so many people can look at it to see the time
"Sunburn" - Reasoning: Sunburn peels when healing, to get rid of damaged skin tissue. Thus, it peels to heal the pain of the sunburn.
"Lampost" - Reasoning: Often, a street lampost will be a source of light above paths that are often travelled at night, hence it the reference to this lonely light guiding you on paths through the darkness.
"Leaves" - Reasoning: Leaves contain veins to transport water through the leaf, and as people would need to be up close to see them. Hence, these veins go unseen as they spend most of their time up in trees attached to branches. You only really get to see them when they fall to the ground.
"A Flag" - Reasoning: Every country has a flag, to represent it, and as such no 2 countries flags are alike. As they tend to be flown up on flag poles, they wave in the wind.
"Midnight" - Reasoning: The riddle is all about following something through to the end - a day. Once the day reaches its end, at midnight, when all the hours of the day are gone, right down to the last second, the clock resets. Thus, it marks both the end of a day and the beginning of a new one.