what if I lost the keystore which generate the CSR

what if I lost the keystore which generate the CSR

Sorry I am a beginner about ssl cert.
according to
http://tomcat.apache.org/tomcat-7.0-doc/ssl-howto.html#Create_a_local_Certificate_Signing_Request_(CSR)
it will gen a keystore and CSR.
we generate the CSR and send to Certificate Authority.
What if I lost the keystore ? should I regen the CSR again to reapply the
ssl cert?
Refer to
https://search.thawte.com/support/ssl-digital-certificates/index?page=content&id=SO832
It will generate a new keystore file.
is it the file store the private key? which stated in
https://search.thawte.com/support/ssl-digital-certificates/index?page=content&id=SO750
, which say
1. Private Key file loss.
2. Private Key pass phrase loss.
3. Private Key file has been compromised due to the server being hacked.
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