We didn't choose to exist. We came into existence, and we will cease to exist. We can feel this life because there is a body with a brain that supports our existence. Who we are without our body or any material association is unclear and is yet to be comprehended. Who we will be without our bodies is still beyond comprehension.
You want to call it soul. Call it.
You don't want to call it anything. Do not call it.
People who existed 400 years ago no longer exist, and people who are yet to exist after 400 years have one thing in common: none of them are currently mortal beings experiencing life on Earth. 400 years ago, we didn't survive, and neither will we survive after 400 years.
Just as life is a journey on this planet, the quest for meaning in life is also a journey. You reach the point from where you start. You no longer see a huge difference between drug addict kids, who are intoxicated throughout the day, and yourself. It is just, that they chose not to explore their meaning in life. You choose and realize there is no special meaning in life. You have to allocate it yourself! And even if you allocate any meaning, it can lose its meaning over a period!
There is a time when people fall in love, and there is a time when people laugh about it. There is a time when people cry over the death of a loved one, and there is a time when people move on from the loss. There is a time when people feel like conquering the whole world, and there is a time when they encounter serious illness that makes them handicapped. There is a time when people amass wealth, and there is a time when that wealth loses its relevance. The funny thing about our sense of free will is that we think we can control our lives, but it is the circumstances that control us. We have very limited control over what happens in our life.
The hairline difference between taking life seriously and not taking it seriously can only be understood by those who have gone through a metamorphosis. This difference can be compared to a person who is yet to be born and a person who is already dead!