So from the main screen you can select any completed quest and go back to it. I'm currently in Act 2 and getting my butt handed to me. I decided I'd like to rerun myself (playing solo) back through Act 1 to level up and re-see some story stuff I missed because of multiplayer stuff.
When I select a different quest it says I'll lose all progress. What exactly does that mean? What will happen if I chose to go back to The Reign of The Black King in Act 1 from Act 2? Will my level, blacksmith level, loot, etc. reset? Or is it just my current progress through the current quest I'm on in Act 2?