I guess it would have to depend on what thoughts about existence are. For me, yes they are the philosophical ponderings of physical and mental existence on this earth, thoughts about how i am just "being here" without really feelilng like it most of the time. But, they are also thoughts about how I exist and fuction in the world. For me that is where the tie-in happens. I believe I exist. I believe that what I do, how I live, how I function in the world is a result of my existence and how I carry it out. From that, I find it extremely important to do things that make me content, that please me, that matter. That is how the real world matters to me. Without the drive to use my existence to create things and help people and work and play and be pleased I would, at least mentally, cease to exist (or at least feel like it).
Does that make any sense????