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