What do you think about the existence of alien lifeform?

Despite there is no direct evidence to support the existence of aliens, we human beings still put effort into finding them. Given the human nature I can see 3 outcomes. One is we eventually find one. Another is we continue searching until the end of humanity.Last one is we somehow prove we are the only life form in the universe. Yet either result is the final step. What would we do if we did find aliens? What would we do if we exhausted all methods yet still no results? What if there are things just not perceivable to human beings? I guess what matters is not the final result, but the progress and efforts we put into it. Given the universe is so huge, what else would you wanna search for?