English Mechanics

The English language is a very peculiar kind of thing. I rememeber back in 7th grade in English class we had a weekly spelling test. He would give us around 15 or 20 words on Monday and we would test on them on Friday. Now these words were never very hard but for some reason I just kept failing them. What caused me to fail them I still don't know since my spelling since then has improved greatly. But what gave me a laugh was the few that I did not fail, I aced. That never did make sense to me.
Now, the English language has always had a very odd way of spelling. Opossum is just one of a list of hundreds of words that the majority of people would miss spell. We have silent letters, as mentioned in opossum, and we also have words where the letters seem to be wrong, such as music (the c makes a very harsh k sound). And if you ask me, these things are pointless. The only reason you would need to be grammatically correct is if you are writing a paper for a grade, or for the public.
But I believe if you are simply writing to communicate with one person, that grammar is not very important. Our minds have a way of reading things even if they are grossly misspelled. There is a common article being circled on the internet that every single word is misspelled, but it is still readable. There are studies that as long as the first and last letters are right, it doesn't matter what's in between.
But also, spelling shouldn't matter, as long as the basic idea gets across. If I were to write musik, you would still know what I mean, the same with possum. But they are misspelled, therefore that shows that spelling is not always an important factor in writing.
Studying grammar, in my opinion is pretty pointless. It will make you look smart in the world of Academia but that is just about it. Knowing where words come from can help understand the true meaning, but words only have the meanings we give to them. Take for instance crap. This word has been changed in the passed decade or two. Once used to identify fecal matter (and still sometimes today) it can be used to say that something is unfair, or even stupid. There are many words like this in the English language. So since the meaning of things can be changed simply by how we use them, it is pointless to try to understand the true meaning, if we are only going to change it.