A print of myself into your memory

When I am down. I fall deeply down. I mope in my thoughts. Sometimes I confide in someone. Sometimes I keep it to myself. Last time I used to vomit out the words into my diary. The thing is, I seem often happy. Really, compare me to any other more unfortunate people around the world lacking in food, water and shelter, I am considered well-off enough. I do not need to worry about the next day and how I can survive. But yet, sometimes I feel down. I've seen more than one friendship that I've had fading away in front of me. And sometimes (maybe because I don't necessary ask for it) , I wonder if I mean anything to anyone. If I am gone one day, will I be missed? Will they just mourn for me until a month or a week is over and put it aside in their mind? Why am I here again? Is there a reason I was born? What if I am actually unneeded? Then what is the point? Is my life meaningless? Those questions are the reason why I try so hard to leave something behind to show that I existed. A print of myself into your memory. A good deed done for a random stranger. Reaching out first to help people. But then again, the things you do for others, they might not always remember. They move on with their lives. And that is just how it is. But what can I do? For now, I don't really know. Because the future is uncertain, although I wish there was some way to know.