Proverbially, to work hard is to "keep your nose to" this
[PAR] Nov 16, 2013 ... My dad always said to 'keep your nose to the grindstone' when he wanted me to 
do my homework.I understood his meaning, that I should work hard until I 
finished, but I didn't know what the proverbial 'grindstone' was, nor... [DOC] [TLE] Inspiration: What About the Proverbial Grindstone?