> i hear this argument constantly, but i've never been able to understand it. you say the universe is big and has existed for a long time, but compared to what?

I think compared to how long it took for somewhat intelligent life to evolve on Earth, from the point of first life. Assuming* a comparable evolutionary cadence, the question then becomes - how often does life begin?

*This I assume because the cadence of living things on Earth is at the very least tied to the day/night cycles, winter/summer seasons, and lunar tides, none of which are especially unique.