When I was a kid I never found much use for grammar. I thought the subject beyond boring and very useless. I never put much effort into it and consequently my grammar was not very good. I spoke and wrote like everyone else around me. I put no thought into the order of my words nor how thoughts should be communicated.
I now need to very carefully and correctly transmit my ideas and scientific results to the rest of the world through peer reviewed papers, posters and oral presentations. One aspect of that is the grammar. I am still working on getting my voice and clearly stating ideas.
The way I really learned grammar was learning spanish. I spent some time in Ecuador (nearly 22 months) and really wanted to communicate with the people in their language. I put a lot of effort into learning Spanish and learning it correctly. While studying spanish grammar I would often literally have flashbacks to sitting in 7th and 8th grade English classes (I had Mr. Foulon and Mrs Gilger) in which the teacher was attempting to help us learn English grammar. I would have a moment of "Oh! That's what they meant. I get it now." What funny moments those were. The reason is that translating incorrect English grammar into Spanish just makes the Spanish garbled and wrong. It sounds and feels wrong. The idea would then work around in my head and come up with a memory that the same thing is really wrong in English but simply ignored in common language.
If you think that somewhere in this jumbled website I have used incorrect grammer please let me know and why you think it is wrong. If your reasoning is sufficient I will readily admit to being incorrect and learn from you.