i used to have a great memory, was a good student, got on in life well enough... then i acquired some substantial brain damage, and lost many functions, including my short-term recall and post-trauma recall.
you didn't say if you used to have a good memory, and trust me, if you can't recall, i am not laughing~! i too finally found ways to help restore my memory. i used knitting to help me regain focus, and jigsaw and crossword puzzles for concentration. these are 2 things that really are important to storing memories, focus and concentration. i think that's why so many who have brain disorders have their memory affected.
i did find a physical therapy that has made huge improvements to my long- and short-term recall. it is called Binaural Beats. you can google it online, but the place that provides it in a therapeutic format is CenterPointe.com.
as for your post seeming to be coherent... that has nothing to do with memory,, i can write many coherent short sentences in a row

and it does not improve my memory~
best wishes~
Gus