Note - I do NOT deny the existence of extraterrestrial life. Given the size/age of the universe I think it extremely likely that life exists on other planets - perhaps even intelligent life.
BUT: here a few things to consider.
The universe is somewhere around 14 billion years old (13.5Bn - 14Bn).All these observations lead me to believe that neither I, nor my kids, nor my grandkids,... will live to see us contact extraterrestrial life.
I'll be generous and take Australopithecus to be "intelligent" in some meaningful sense. The genus Australopithecus arose 3.9 to 3 million years ago.
3.9Mn vs 13.5Bn.
The universe was 99.97% of the way through its current age when Australopithecus appeared.
Australopithecus had not the technical ability to contact extraterrestrial life.
Our species, Homo sapiens evolved around 250,000 years ago.
The universe lived without us for about 99.9981% of its life till now.
Until less than 200 years ago, we (Homo sapiens) hadn't the technology to contact extraterrestrial life.
It'd be a lot easier to contact extraterrestrial life if E.T. had comparable technology. We've only had our technological ability for about 0.08% of our time on earth as a species.
All those other folks live way far away!
Nearest non-"our sun" solar-system? Alpha Centauri, about 4.3 light years away.
Nearest non-"Milky Way" galaxy? The Canis Major Dwarf Galaxy, about 25,000 light-years away from our solar-system.
p.s. the above should not be construed to mean that I believe we are unlikely to find life on some other planet within our solar system - only that "contact" in this case would mean something different from that considered.
Note: we live in a weird world - a world that would be almost unrecognizable by our great-great-grandparents.
Loud machines flying through the air.
Loud machines with wheels running everywhere on hard-surfaced roads.