why do I need no-cache header?

hi all

every page in wordpress has the “wp_get_nocache_headers” headers (nocache, expires in the past) – can I remove it in my theme and make my pages cachable and expire after 1 hour? this will speed up the browsing after visiting the page the first time and will only interfere the comments but they are not visible until the admin approve them anyway.

Am I missing something here? Is there any reason I shouldn’t do that?

thanks in advance,
ofir