The biggest harmonica beginner mistake

I just finished a lesson with a beginner student and what puzzled him the most was how to get a clean tone on his harmonica. I showed him the right position after he tried for couple minutes and couldn't get a good tone he said: It seems something is wrong with my harmonica. I assured him nothing was it's just a matter of technique, I broke down the position again showing him closely what to do, 10 more minutes go by he can almost play one note at a time but the air is leaking a bit on the sides it's definitely not a clean sound. Then He looks at me and asked "is it better?" I replied " yes a little bit now you're close to getting only one note at a time. He tried again for couple more minutes then said "Hmm, it's much harder then I thought!" I replied "Welcome to the club!".
Here is the takeaway: Everybody thinks playing the harmonica is easy because they see kids play one (usually not well) or they had someone in the family playing a few tunes on a harmonica. Truth is learning Harmonica is actually as difficult as any other instrument we could even argue the beginnings are harder because everything relies on playing a clean sound which is definitely not given.

If you try to play the piano you will easily be able to play one clean note on your first minute but for Harmonica it might take weeks or more!