In games like Pathfinder: Kingmaker, you are constantly asked to take decisions. What character class do you want to play? How do you want to level up your characters? What alignment do you want to be? Which quest do you want to do? And at the start of the game, you make many of these decisions without knowing their consequences, because you don't know the game yet. Decisions based on incomplete information can easily lead to regret. Imagine for example that your first decision in Pathfinder: Kingmaker is to make your character a female barbarian. And then after the prologue you find out that the female barbarian Amiri is now part of your group. You sure didn't want two of them in your group!

Me, I made a cleric and found that among the companions that join you over the course of the game there are two clerics. But no wizard and no sorcerer (you get a sorcerer for a short while in the prologue, and one multiclass rogue/wizard). You can spend a lot of gold on making a custom character "mercenary", but you have to play your main character, and the mercenaries come with certain disadvantages like lower stats. So for my second go I made a wizard main (I'll do a sorcerer mercenary too), because not only does that give me access to lots of arcane spells, it also gives me a character with lots of skill points, which is useful for a main character. The sorcerer is probably better for number of spells per day and damage output, but the wizard has the better variety and gets higher level spells earlier.

The information about the character classes of the companions wasn't the only thing I learned in the first go. I also learned a lot about the Pathfinder system in general, and the flow of the Kingmaker CRPG in specific. For example, each chapter has a time limit in in-game days. If you don't do the main quest in time, you lose. But if you are too fast, the extra time is lost, and you might regret not having done some other things before finishing. I also learned that if you don't choose lawful as the alignment of your main character, you'll lose a companion in chapter 3, which was annoying. Also I learned how the kingdom management part of the game works, which is another thing one is likely to not get perfectly right on a first try. My first kingdom was doing fine, but I had somehow missed out on putting enough effort into "divine", which meant that I never got an advisor for "arcane", which really hurt me with working on the curses.

In short, I felt that only by playing the game I was learning enough of the game to "play it right". Once I found out a lot of stuff about the game, I had regrets about decisions taken earlier, based on incomplete information. Other than using external help and guides, I don't really see a way around that.