Since Reunited revealed that it has been eight months since Steven's birthday (season 2!), then let's see how much has happened since then.
- Steven learns of the Earth's plans
- Peridot becomes a Crystal gem
- Malachite defuses
- The Cluster is bubbled
- Lapis decides to stay on Earth at the barn
- Rubies come to look for Jasper
- Steven discovers his floating powers
- Greg gets rich
- Peridot gets a tablet and discovers her ferrokinesis
- Steven discovers his mind-transfer powers
- Steven manages to partially heal Centi
- Steven and co. find Jasper at the Great North
- Jasper returns at the beach and poofs Amethyst
- Steven and Amethyst fight
- Steven discovers the existance of Bismuth and has to poof her again later
- Steven, Amethyst, and Peridot find Jasper at the beta Kindergarten
- Steven and Amethyst fuse
- Jasper fuses with the snow monster and becomes corrupted herself
- Steven learns Rose shattered Pink Diamond
- Crystal Gems take the Roaming Eye from the rubies
- Peridot bubbles her first gem
- Stevonnie is now able to stop halluncinating
- Pearl meets Mystery Girl
- Steven discovers the existence of Andy DeMayo
- Greg is kidnapped by Blue Diamond
- Crystal Gems save Greg from the human zoo
- Navy steals the Roaming Eye back from the Crystal Gems
- Topaz and Aquamarine come and start abducting humans
- Steven sacrifices himself and goes to Homeworld
- Steven is put on trial
- Lars dies and is revived, causing Steven to discover his reviving powers
- Steven and Connie have a fallout
- Nanefua becomes mayor
- Lapis leaves with the barn
- Steven and Connie reunite
- Steven discovers Lars became a space pirate
- Stevonnie crash lands on the Jungle Moon and sees a flashback of one of Pink's memories
- Stevonnie returns home
- Garnet tells the off-colors the story of Rose Quartz
- Garnet adopts Cat Steven
- Steven finds Lapis on the moon, but she flees again
- Steven learns that Pink Diamond faked her shattering and is indeed, Rose
- Garnet unfuses
- Pearl tells the real story of Rose Quartz
- Ruby proposes to Sapphire and later get married
- Blue and Yellow Diamond come to Earth and pop the Cluster's bubble
- The Cluster partially emerges, and is on the Crystal Gems' side
- The Crystal Gems fight Blue Diamond
- Peridot and Lapis are poofed by Yellow Diamond
- Steven convinces Blue and Yellow Diamond that he is Pink Diamond
And that's all. :)