The reason you need to smell your vagina everyday is to alert you to any change in the odor which could be a sign of a UTI "Urinary Tract Infection" or other health issues with your Vagina.
You should know what your vagina smells like when normal so when you do take a whiff of your vagina and it smells different then it could be a sign of something wrong.
Then if you do notice a change in smell of your vagina it would be good to talk to your doctor about it.
It's normal though for vaginas to have an odor to them and sometimes the odor may change from day to day which is also normal.
But if you notice a really foul smelling odor or a fishy smell from your vagina then it may be a sign of a Urinary Tract Infection.
A urinary tract infection usually clears up on it's own but you should see a doctor just to be safe.