Before we made contact, humans were considered a myth, the Galactic Governments greatest hoax. No one species could possibly be THAT insane.
It's very stressful for the rest of the Galaxy when they discover humans are indeed real, and just as insane as they'd heard. -- Anon Guest
Everyone in the Galactic Alliance knew the stories that spacers told of humans. Near misses. Close encounters. Abductions. Scouts told stories of dead worlds where relics of these peculiar, hairless, bipedal mammals had once reigned and then destroyed themselves. Tales of impossible wreckage that should have killed all aboard on impact, yet the surrounding area showed signs of habitation before it was seemingly abandoned.
Scavengers, scroungers, and asteroid prospectors would swap tales of meeting humans. Some would even exchange what they believed to be human entertainment media. Transcribed, of course, into more usable formats, which always caused the source to be questioned. The stories were always larger than life. How first contact situations happened purely by accident and the human vessel in question was never found again.
It wasn't until the Armoured Cephalopod came to answer the distress call of a scavenger ship named the Corvid that an encounter was confirmed. Also crippled on the dwarf planets' surface was a human vessel. The saurian scavenger and the human had accidentally crashed and forged an alliance based on the simple fact that they were clearly going to die on their own.