use of "where" and "what"?

Hey Tron,

I am Shruti and this is my first ever enrollment in a language course.I’ve always had some strange affinity with this language and want to perfect it wholly. I want to command this language flawlessly, perhaps the only reason why I’ve joined this forum. I am sure this association is going to last forever and it will be mutually beneficial for both of us.
A thing more which perhaps explains why I am here," During my school days I hardly paid attention to the language and its grammatical nuances."

Hpe to see your next newsletter soon