I don't think you have to be particularly self-centered to entertain the idea that we might be first. Despite the 8 billion year head start an alien civilizatio

I don't think you have to be particularly self-centered to entertain the idea that we might be first. Despite the 8 billion year head start an alien civilization could have if it developed at the same pace as we, just early on, we see no evidence of any aliens out there anywhere. (And, despite billions of cameras, there is no evidence of any aliens here.) We ourselves owe our existence to a chance extinction of the dominant life form on Earth 65 million years ago. Without that, our mammal ancestors would not have been able to reproduce as frequently and plentifully, which would almost certainly have slowed the development of us if it didn't rule it out outright in the timescale the Earth has left. There's no guarantee most worlds with life even ever develop multi-cellular life. It took Earth billions of years to go from single-cell to multicellular. Yes, there has been a lot of time and a lot of star systems, but there are so many things that are required, I'm not at all confident that there is intelligent life out there. Earth is a sample size of 1, and we tend to treat it as if its the norm, but that's just a sometimes-useful assumption. The reality is we might have won the universal lottery.