I'm doing it the same way, it's just very common to underestimate how hard things are when you're good at something. This is among the most common problems for e.g. beginner game developers, and why you can almost always be sure that you will never be able to beat someone's first computer game. I thought #modarchive story was "normal" when I created it.
A good guideline that I always use today is "Label every difficulty one or two steps above what you'd think yourself, depending on how good you are". This rule would have worked very well on the forums, I personally find most "Normal" knytt stories user levels to be hard, and I'm still the main designer of the game.