Turns out, I'm not a serious player :( because I only make one save per day, almost always.
1. You have a lot of free time and you can afford to replay the entire day from scratch because of one wrong battle. Or...
2. You've never had to create a step-by-step report of your playthrough, where someone might ask you to explain every move of each hero. I wonder, what's the maximum number of heroes you've ever controlled in a single day in your experience? :) For me, it's about 20 heroes, and one game day takes about 7 hours of real time (sometimes more - it all depends on how seriously you're playing
