Starhawk writes: "Well possibility is that we are the oldest sentient species, anyone ever consider that? No....why?"
This is of course one of many POSSIBLE explanations, as I suggested earlier. However, since solar systems capable of supporting terrestrial-type life almost certainly formed billions of years before our own, it SEEMS unlikely. I use the term "seems" because with only one data point we can't actually calculate the odds.
Of course in a sci fi setting with many alien species, the more aliens, the less plausible it is that humans are first, or even comparably advanced.
Isaac Asimov has used the "humans first" premise either implicitly or explicitly in several of his stories, notably the "Foundation" series, his short story "The Last Question", and his novel "The End of Eternity". In this last novel, humanity squanders its head start by wasting 10 million years (a cosmic eyeblink) using temporal technology to "improve" human life on Earth, which inadvertently postpones interstellar travel until too late.
These are all great stories despite their failure to deal explicitly (or convincingly) with the "FTL yet humans first" paradox. If, however, an author makes a good effort to resolve the paradox, thereby at least making unlikely premises more self-consistent, then so much the better.