There are great answers in this topic. Here is some more input:
So my only conclusion is that they didn't want me to play what was on the page.
Oh yes, you can play what is on the page, but a forte section or a piano section is not just about playing all the notes at an equal volume in that section.
Focus on phrasing. Like you can go up and down in volume within a piano section, but you are still playing an overall piano and similar with forte and other dynamics. You can sometimes make a slight increase or decrease in tempo, it can be quite subtle, the overal tempo is still intact.
Sing or hum the melodic lines because then you can directly feel the melody, then play similar to the way you sing or hum.
Phrasing includes articulation, like you can play a staccato very pointy or less pointy. Or you can play some notes a tad longer or shorter than other notes meaning releasing the key sooner or later unless they are supposed to be played legato of course.
Just like you can utter a word or a sentence in a lot of different ways you can also play in a lot of different ways and yet play what is written in the sheet music.
You can play a piano section in a similar way you would pat a cat, softly and gently and there you are already playing with feeling.
You can play so it feels like a thunderstorm, of course only if the music is in a style that would give inspiration for that. It might give a better forte expression if you feel it is like a thunderstorm instead of just thinking about a dry forte.
So work with phrasing, get the hang of phrasing or the feel of phrasing and include some metaphors now and then, like the metaphors I mentioned above (patting the cat and the thunderstorm) and you might discover a new and fantastic dimension and experience of music.
