This isn't a second correction to your notebook, just to your comment under my correction. (I need formatting, and can't get it in comments.)

> today I promise to never forget third person's rule! (Is correct without article?)

That's an interesting question. The short answer is no, you (usually) need the article. The longer answer is below.

The first thing to note is that this isn't the third person's rule, but rather the third person rule. Possession is used when someone owns something, or if they created it, or it was in some way discovered by them. For example, Maxwell's equations are so called because they were discovered by James Clerk Maxwell. However in this case the rule doesn't belong to third persons, nor was it invented by them; "third person" is just an adjective describing what type of rule it is.

But if the rule does "belong to" someone (like Maxwell, for example), then you do use the possessive. And if you use the possessive, you no longer need an article.

For rules or laws (whether of grammar, maths or physics) you would use either an article or the name of the creator / owner of the rule:

1/ The relationship between mass and energy is given by an equation in the theory of relativity. (We use an indefinite article, because we aren't specifying which equation.)

2/ The relationship between mass and energy is given by the equation E=mc^2. (Definite article, because the equation is specific.) 

3/ The relationship between mass and energy is given by Einstein's most famous equation. (No article is needed, because "Einstein's (etc)" establishes which equation; it replaces a definite article.)

Just watch out for:

4/ The relationship between mass and energy is given by one of the equations in relativity. Why "the" when we haven't identified which one? Because we have said "ONE of the"; we are therefore referring to one definite object, even if we have not specified which one.

Wheatfield under Thunderclouds

"""""""""""

Excllent English - very high level. Only small suggestions above. Yes, nice painting and interesting report on the art gallery. Thank you. 

We can be completely happy - but we can like things a lot - not completely 

Normally a sentence should not begin with And. Sometimes we can see this rule broken, and there is much discussion online about this. However I would say normally do'nt do it - maybe for emphasis. And, another thing.....

Wheat Field under Thunderclouds

"Like" is the verb, "completely" is the adverb. As with adjectives and nouns, adverbs generally come before the verb rather than after in English.

And these glasses change this glass changes the possibility to "live" the paintings.

1/ I know why you said "these glasses"; they are individual panes of glass. However "glass" in this sense is just the material that the barrier is made of. it's not regarded as being a countable object. "These windows", yes. "These panes of glass", yes. Drinking glasses, yes,. spectacles (occhiali), yes. But when it's just the material and not the units of the material, then it's "this glass".

2/ You can't really "live" a painting. I think that the concept that you're getting at is "...changes and limits the way that we can immerse ourselves in the paintings"

There are reflections, and you lose the feeling with the of Van Gogh's brush strokes.

1/ You have a feeling OF something (or something like this, anyway), not with something.

2/ If you had not said "Van Gogh's", you would have used used "the". However "the" is used as a definite article; it means that you are referring to specific brush strokes. In this case you don't need to though, because you have specified that they are Van Gogh's brushstrokes. That is enough to make them specific. Yes, this is more of your life spent on the definite article. Sorry about that.
But, anyway, I love this painting. I adore its colors, its saturation, the sensation of calm and peace.

"I adore colours" means that you adore colours generally. In this case you are talking about the colours of the painting. You therefore need to qualify it with "its". ("Its" is possessive but does NOT have an apostrophe s.)

It gives me the same sense that give me the a landscape gives me before, or maybe after, a thunderstorm.

1/ It is singular; singular in the third person (he, she or it) gives. I give, you give, he she or it gives, we give, they give.

2/ The way you had the word order, you were saying that something was giving you a landscape. Instead what you mean is that a landscape gives you that sense.

Wheatfield under Thunderclouds