@elextr Thanks for the explanation elextr. I did not know that /tmp/ gets emptied and indeed the note that you mention could have give me a hint even though I would not think it would apply to the default directory which geany selects(tmp).
Lots of people who switch for geany come from notepadqq or notepadd++ and whenever you open a new note and don't save it and restart your pc, you can retrieve it, so many people are used to this default safe behavior.
+ Seeing a file with a filename created automatically by geany really implies for me that it must be saved somewhere where it won't be deleted.
I changed the default saving folder now of course