To exist is to be perceived.
Eighteen years of wandering in this road called life made me realize that my existence in this world isn't just about me sleeping, eating, having fun, studying, and doing those other day-to-day activities. Rather, it is how gracefully I lived my yesterdays, how boldly I am facing my todays, and how wisely I will prepare for my tomorrows. Whatever perceptions other have for me at the present, due to the actions I have taken in the past, can be considered as evidences of what I will be in the future.
But to exist isn't just to be seen, heard or felt by others. To exist is to be involved. Yes, you may have friends, but simply having friends is different from having these persons whom you care about, think about, and share your problems with. Yes, you may have a family, but simply having a family is different from having a father whom you think about whenever he goes to work, a mother whom you help with the household chores because you can see that she is very tired, brothers whom you look up as models and you try to emulate, and a sister whom you protect from any possible harm or disappointments. Yes, you may have a special someone, but simply having a special someone is different from having this person so close to your heart whom you never fail to think about, whom you always want to be with, and whom you want to share your whole life with.
This means that there is a big difference between simply "being here" and actively "existing here". The former connotes a mere physical appearance while the latter implies a deep spiritual connection. In the first one, people around you knows you are here simply because they can see that you are here, while in the second one, people around you do not need to physically see you just to know that you are with them.
Unfortunately, it took me eighteen long years just to realize this simple fact:
It is only when we start to care about the people around us do we gain the experiences required for us to grow and mature. The different emotions and feelings that we have toward others and that we keep and nourish inside of ourselves help us develop a strong and distinct personality. If people would only start to take care more for others, they will never need to take care for themselves because each one of them will take care of each other. And from that, Heaven will finally be realized here on earth.