Always providing the wrong answers from the wrong point of view.

Your last sentence should prove to yourself that you really have no business in trying to teach anything about music. If anything, you need to start learning/re-learning.

 

Generally in a song, if you play all the chords in song's key, it will sound boring and somewhat predictible. This is why you hear all kind of tricks like diminished chords, missing chord notes, or, as you realised, strange chords which make the song "cool". It's just how it is. I noticed that Eastern Europeans are very sensible to any kind of dissonance and they rarely use it. As opposite, the Westerners (USA included, especially jazz players) are really into dissonance. So my advice is: if you're Eastern spend a little more time understanding the West way of making music, and if you're Westerner, just keep on playing with chord combinations to get something beautiful and unexpected.

 

Wait... what?

You might be confusing dissonance with "out of tuneness".

 

dissonance is a beast not for everyone.

kids sleep well under a perfect cadence.

 

A tritone is pretty dissonant.

I can't believe anyone gets scared by a V7 I (or i) in this day and age, even in children's music.