Carpe Diem--"Seize the Day"
Perhaps this sense of "waiting" or not living every moment to the fullest is in some way related to a mind and heart that's living in the past and maybe even the future but not in the present. An example of living in the past would be that of living in guilt. The feeling of guilt can only exist as a result of a past action. Living in this guilt can paralyze a person from living in the present. Living in the future can also prevent us from fully living in the present. As one looks ahead to what's to come, one's heart may be filled with many "if"s and may become gripped with fear...whether it's fear of change in oneself or in one's environment or fear of failure, etc.
So, I guess this feeling of waiting for something and of being a spectator of life has to do with a heart and mind that is divided between the past and the future. You know, it seems to me that to live in the past or in the future is so much easier than to live in the here and the now, where things may be messy and sticky or just plain and ordinary, seemingly without much excitement. Now, that is not to say that I never reflect on the past or look ahead and plan for the future, but that I should not be LIVING in neither of the two. No, I need to learn to live in the present, for as C.S. Lewis states, "...the Present is the point at which time touches eternity...the Present is all lit up with eternal rays" (p.61-62, "The Screwtape Letters")
O Lord Jesus Christ, teach me to live in the here and the now, in the present. Gladly submitting to whatever it is you bring my way.