Anyone who has not made mistakes has not tried something new.
I've made a few mistakes (such as letting my Dynasty heirs slack off
), but from them, I've learned. My biggest mistake was building too much at once. Back when I cheated a lot, I built a humongous underground complex for my Dynasty family, which caused many traffic issues, many delays getting to work, and all-round headaches. It spanned probably five floors, with a giant playground, pool, courtyard, hedge maze, and many, many bedrooms. I was also a fan of tomb traps at the time, locking the spouse in the sub-sub-sub-basement, and playing around with glitches. I loaded that file recently, it was only first-generation but took around 40 minutes to load, and something like 3 minutes to render items.
From that, I learned to build modest houses.