Short answer: Because Forge saves for you. Edits apply themselves about half a second after you stop typing - or as soon as you press Enter or click away - and the stage updates immediately. The top-bar indicator stays quiet when work is saved and calls out saving, unfinished edits, offline work, conflicts and failures. Invalid values are held until you fix the field. If you change your mind, Undo steps back.
When an edit saves
An edit commits on its own about half a second after you stop typing. Pressing Enter or clicking away saves right then. Switching to another event also saves whatever you had in progress. You never lose work to a forgotten Save click, because there is no Save click.
Invalid values are never saved
If a field holds something Forge can't accept, the edit is held - not saved - until you fix it. Your project keeps its last good version in the meantime, so a half-typed value or a broken entry can never land in the story your readers would play.
The save indicator
The indicator stays quiet when the project is up to date. While work is pending, it can show saving, unfinished edits or offline work. Save failures and conflicts stay visible; press the failure indicator to open Problems. Problem rows link to the relevant scene or line when that location is available.
Undo, but no Redo
Undo steps back through your recent edits, one at a time. There is no Redo in the story editor - once you undo something, the way to bring it back is to make the edit again. (The Theme and title-screen editors have their own undo and redo.)
Deleting is a deliberate action
Removing an event is never part of autosave - it's its own action, and by default Forge asks you to confirm before deleting. You can adjust that confirmation in Forge's settings.