Can one have too many standard lenses? That's like asking a chocoholic if he ever had enough chocolate. Of course not. Standard lenses can be made very fast, and usually a lot cheaper than other focal lengths. You can have more, for less, so to speak :-)

Here are some of the standard lenses I have, from left to right.

Top Row:
Canon EF 50mm f1.4, Canon FL 55mm f1.2, Canon FL 55mm f1.2, Canon FD 55mm f1.2 SSC, Canon EF 50mm f1.2L

Midlle Row:
Yashica ML 50mm f1.7, Chinon (Tomioka) 55mm f1.4, Ricoh 55mm f1.4, Cosina 55mm f1.4, Petri 55mm f1.4

Last Row:
Leica Summicron 50mm f2, Minolta Rokkor 58mm f1.4, Fujinon EBC 50mm f1.4, Rollei Carl Zeiss Planar 50mm f1.4, Olympus OM 50mm f1.4