The lyric expresses a longing to know more, but alas, we are forever confined to our senses; similar to Kant's perspective, which suggests that, although we can know information about a thing (i.e., via the senses, "touch" and "see", as the lyric suggests), we can never know a thing in and of itself (i.e., outside of our senses). We can only ever experience a sense-based representation of a thing, and not the thing's true nature.
Moreover, we cannot touch (i.e., experience) or see (again, experience) anything outside of the present moment. No matter what changes, we are locked in the moment, because there is no past or future, in the sense that we can experience those concepts now (i.e., there is only the present moment in time). Everything that has ever happened, occurred in a series of present moments.
The lyric expresses these truths, while intertwined with a saturnine feeling; that is, we are bound by our senses, and bound by the moment, but we long to experience more. However, it is all we ever have; it is: "all your life will ever be."
Touch sth. with your hands? Or touch it with your mind? Is all everything? Or just the things we can remember? Do your eyes see everything, or only the important parts? Do you remember every second of your life? Can you remember everything?
Read my damn words twice.
