To answer this very question, I would like to quote someone and that is "The absence of evidence is not the evidence of absence.
Yeah. For all we know there could be intelligent life out there where we seem no more intelligent then a goldfish does to us. We just do not know. If I had to take a guess, I would say there is life or something that is more intelligent than us out there/somewhere.
Indeed, I fully expect our known concepts of outer space neighbours to be thoroughly challenged if we ever do meet one. Like you, if I were to make a bet, I'd say yes.
It's simply mathematically impossible to not have aliens. Imagine billions of galaxies (even outnumbering the entire human race) and our speck of dust is the only one which has lifeforms?