There's so many ways to think about that and knowledge is power but ignorance is bliss.
Rene Descartes decided that the proof of his own existence was in the observation that he thought - had a mind that could think. So he decided that because he could think, he must exist.
I think. Therefore I am.
On a side note, this very guy once walked into a bar and ordered a drink. Bartender brought him a drink. After a while the barkeep noticed his glass was near empty. Another drink, Mr. Descartes?
I think not, said Rene.
And disappeared.
But really, people say that shit like, "you matter to the people who know you". There's so many jobs where people sit in cubicles next to all these other people for 8 hours a day, 5 days a week, and yet know nothing about each other. If you're saying that to someone who's constantly moved around or actually doesn't have a close circle of friends with a shitty job then what are they really holding on to? In comparison to that you can see examples of celebrities or just insanely accomplished people who have overdosed purposefully but seemingly had it all. Some guys always got it better and some guys always got it worse you just have to find what makes you happy or a way to vent your sadness.