new install: how can i not have enough space?

["Robert P. J. Day" <rpjday crashcourse ca>]

argh!  i just started a new install on my laptop, so i could divvy  
things up into numerous logical volumes.  i selected a pile of  
software, only to be told that my selected packages require 4698 MB of  
space and i don't have that much available.

excuse me?  i have separate LVs for /, /home, /usr, /var, /tmp and  
/opt, with the *smallest* of those being 5G (/usr is 16G, /home is  
50G, all the rest are 5G).  how exactly do i not have enough space  
with 16G for /usr?

rday