"Tell me everything you know!"

I wish I could tell. Every time I try, I fail miserably and break into dialogue, vocal inflection looks, smiles, frowns, grunts, physical gestures vocal tones, etc. I actually have to act scenes out in order to get the gesticulations accurate! (Though I suppose it does count as exercise, so I've got that going for me, which is nice...)
It looks so easy to tell, - you go on 6 sentence paragraph followed by two or three lines of dialogue followed by an 8 sentence paragraph, followed by two lines of dialog, on and on, etc So why the hay can't I do it?!!
You can tell the readers exactly what each character is thinking, no need for the readers to think for themselves. It makes for much easier reading and is far more economical. You don't even have to worry about breaking character! Without the nuisance of dialog, you can tell the reader how the pony is feeling and why they're feeling that way. The reader can supply the voice they know from the show and everypony's happy.
I respect my readers. They accept my flaws even though they know it's more challenging to read dialog and have to work through the complexities of body language as it relates to emotion and to draw their own pictures (except where I feel compelled to add a PMV I've created or a piece of fan art that just blew me away) The minute I step outside of character, they know by the dialog, and point it out and I feel awful (Well not all the time.) I've tried, I really have, to buckle down and just tell the reader everything, but alas, I am unable, so what can I say - "the show must go on..."