The phrase "ago we discover" is not correct in written English.
It seems to be a mix-up of time expressions and verb forms. An example of a correct phrase could be "a year ago we discovered."
Alternatives: "previously we found" or "in the past we uncovered."
Years ago we discovered that if we thrust ourselves into the falls, holding our breath while withstanding the force of the water, we could make it to the other side and sit in the cave breathing freely, the water inches from our faces.
A couple years ago, we discovered that Italy's new electoral law was unconstitutional.
"Following the New York attack that occurred a few months ago, we discovered pieces of ISIS and Al-Qaeda propaganda online encouraging these types attacks," CEP's senior research analyst Josh Lipowsky told VICE.
"About two years ago, we discovered the whole brave new world of video," Vladimir Ashurkov, one of Navalny's top allies and Executive Director of Navalny's nonprofit, the Anti-Corruption Foundation, told VICE News.
First of all, a few months ago, we discovered, tucked away in the Cologne conclusions, in paragraphs 44 and 45, the decision to start drafting a Charter of Fundamental Rights.
"A few years ago we discovered the Ghost Slug, which became one of the top 10 new species discoveries of the year.
Four years ago we discovered the Portable North Pole (PNP).
When I explained, he said, "Rufus will pay for this, he will pay the debt!" I never had a clue what he did after he left – it was only a few years ago when we discovered that he was directing a play in Malvern.
A few generations ago, before we discovered such things as credit cards and floating debt, our parents, grandparents and those who came before us were remarkably resourceful people who worked with their hands, who helped their neighbors, and who didn't believe in wasting anything of value.
However, this selective cap on adiposity was effectively removed around 2 million years ago when we discovered fire, became social animals and invented weapons.
