Is caching necessary?

[Pepe]

Kevin Darcy escribi=F3:
   > Lorenzo wrote:
   >>I have a DNS server setup for my home LAN. Yes, its a bit much, but
   >>everyone needs a hobby.
   >>[...]
   >>Currently, I forward my queries onto my
   >>ISP, which if I understand things correctly, means I'm not caching
   >>anyway.
   >
   > No, forwarding still caches, and you're benefiting from that caching=

   > behavior.
   > [...]
   > P.S. Why are you forwarding? Does your ISP block queries directly
   > between your nameservers and Internet nameservers?

If not forwarding to the ISP nameservers, should his LAN nameserver
query the root nameservers for any and all zones he is not authoritative
for? Would not this, if done by everybody, overload the root nameservers?=