Fetch As Google Bot Evaluation

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1

When I use webmaster tools and see the coding like Googlebot sees it, I see this at the top of the coding:

HTTP/1.1 200 OK
Date: Thu, 14 Jun 2012 16:32:18 GMT
Server: Apache/2.2.21 (Unix) mod_ssl/2.2.21 OpenSSL/0.9.8e-fips-rhel5 mod_auth_passthrough/2.1 mod_bwlimited/1.4 FrontPage/5.0.2.2635
X-Powered-By: PHP/5.2.17
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Pragma: no-cache
Set-Cookie: PHPSESSID=97696e81ee6760aca2b369db89d1641a; path=/
Set-Cookie: cookie_sid=gan; expires=Fri, 15-Jun-2012 16:32:18 GMT
Cache-Control: max-age=864000
Vary: Accept-Encoding
Content-Encoding: gzip
Content-Length: 6145
Keep-Alive: timeout=5, max=100
Connection: Keep-Alive
Content-Type: text/html

I am wondering why the expire date is 1981 - where is that set?

Also worried about why this line is in there and what does it mean?

Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Pragma: no-cache

What can I do to better the performance of this page?

Thanks