For a long time we weren't at all sure whether the expansion of the universe would stop, leading to a "big crunch", or continue forever, slowing down for eterni

For a long time we weren't at all sure whether the expansion of the universe would stop, leading to a "big crunch", or continue forever, slowing down for eternity. Then we found the other option appeared to be supported by observational evidence: the expansion is accelarating. We're in a similar position with finding life elsewhere. The vague error bars in many terms in the Drake (so-called) equation shouldn't be read as indicators of (im-)probability, more as signs of major gaps in our understanding. We slowly inch towards better data. Surprise is likely on the journey. I would say though that, so far, we're pretty sure there is some life in the universe, but nothing else.