This is not about being depressed/bad situation in life and thus ending one's life. I do not mean that.

My point is, what pushes you to keep going forward?
Life is a lot of things, doing good working, building profound human relationships, making a family. Having fun. Being a wageslave etc... etc..
All of what is mentioned above, is temporary state of happiness. These will all end in the end, whether good or bad.
Philosophically, why shouldn't I end my life?
My life isn't the best life, nor the worst.

Religionists, please keep religion to yourself.