I created an assembly Assem1 and created an virtual subassembly in it called Assem2^Assem1.

I opened Assem2^Assem1 in an new window and did many jobs in it.

Of course I have a practice to press "Ctrl + S" frequently, and I THOUGHT my changes are saved on my hard disk!!!

But I didn't save Assem1 when I closed Solidworks, so all my work is gone.

Why Solidworks is not smart enough to save my work on hard disk???