For longtime Marvel Comics fans, the sight of a red-faced dude opening his eyes at the end of the latest trailer for May’s Avengers: Age of Ultron was something to get excited about — but for everyone else, it might have seemed like a confusing anti-climax after the chance to see the Hulk, Captain America and Iron Man kick the asses of an army of marauding robots. What are those people missing? Only the chance to see the on-screen debut of the Vision, Marvel’s least-likely romantic lead and a robot that taught the world that even an android can cry.

The Vision first appeared in 1968’s The Avengers #57, launching an association with the superhero team that continues to this day (He’s currently appearing in the Uncanny Avengers series, having also anchored Avengers A.I. and Avengers West Coast throughout the years). The creation of writer Roy Thomas and artist John Buscema, the Vision was originally introduced as the robotic offspring of Ultron, albeit one so human that he turned against his “father” at the earliest possible opportunity to become a card-carrying superhero.

What made the Vision so human was apparently the fact that his robotic brain was programmed using the brain patterns of a human — Simon Williams, to be exact, a former enemy of the Avengers who was dead at the time. (He’d later recover and join the team himself, with the Vision and he referring to each other as brothers.) It was just one of the many pieces of recycling that Thomas used in the character’s creation; it would later be revealed that his robotic body was that of a former Marvel hero called the Human Torch — unrelated to the Fantastic Four member of the same name — and even the name “the Vision” had previously been used by an entirely separate superhero owned by the publisher.

Despite his unoriginal roots, the Vision became a favorite of readers and writers alike, in part because he gave Thomas and the many writers that followed their own version of Star Trek’s Spock to play with; although the Vision had many impressive superpowers — he can alter the molecular density of his body, allowing him super-strength and the ability to walk through walls and fly, and the jewel on his forehead collects solar power that he can then shoot people with, all thanks to comic-book science — the character was soon known more for his constant musings on the nature of humanity from an outsider’s perspective and overwrought emotional turmoil than any actual superheroics he might have attempted.

Much of his emotional turmoil centered around another character being introduced in Avengers: Age of Ultron: the Scarlet Witch. Wanda Maximoff, as her friends call her, was already the potential love interest of a number of male Avengers by the time the Vision was introduced into the series, but his sensitivity and kind heart — or, at least, the robotic equivalent — won her over in a long-running storyline that culminated not only in marriage (which happened in 1975’s Giant-Size Avengers #4), but the birth of two children at the end of a 1986 mini-series titled The Vision and the Scarlet Witch, the second of the Vision’s turns as a leading man outside of the Avengers.

(If you’re wondering quite how a robot could get anyone pregnant, the answer is literally “magic”; the Scarlet Witch used her powers to make it happen, only for that to be undone three years later when it was revealed that the children were actually made up of parts of a supervillain’s soul and not actually real, and — well, let’s just leave it as “comics can have some pretty weird ideas sometimes.”)

In his career, the Vision has suffered many indignities that only an android could endure: he’s been reprogrammed, contracted viruses and rebooted on more than one occasion; he’s been destroyed multiple times, including being torn to pieces by the Hulk’s equally gamma-powered cousin, She-Hulk; and he’s even been turned into a supervillain when an egomaniacal computer managed to convince him that becoming a benevolent dictator was in humanity’s best interests. Throughout it all, he’s remained a fan-favorite character who has never stopped searching for ways to grow and improve his own life, and the lives of those around him. If the big-screen version has even a half of the charm and appeal of his comic book counterpart, the Vision might go on to become the most popular — and most human — hero in the Marvel Cinematic Universe.