Those who have left this world can never come back, when one misses them, one becomes very sad. Then the only thing that comes to the human mind is that one day we all have to leave this world. life is not going to stop anyone from going, we have to live it just like before in our own way. In the beginning, a person is very worried, but gradually, a person gets patience. My friend also had a dog and then he passed away due to some illness so he still gets very upset whenever he misses him. And since then, he has never had another dog. If he had picked up another dog, he would have remembered his previous dog when he looked at it.
You are so right. We will all have our expiration date but the very best thing is to extract all of the joy we have from the days we have left to walk this earth.
Yes you are right we should live our every day properly because none of us know when we will leave this world.