A few newbie questions

[Michlo]

Forgive me if I just missed where this was but I need help with the following:

why can't we always upgrade units (sometimes the upgrade is greyed out)?

the military advisor doesn't seem to be very helpful this time around, can we not do any global upgrades, etc?

Thank you in advance.

[Ninot]

Maybe you don't have the resource needed?

Maybe you don't have the gold required?

[Michlo]

*smacks self and blushes*

Err, hmm.

I'm at a point where I'm far more advanced than everyone else right now but I've been spending gold to build up a little island I have up in the ice so I didn't even think about the gold I would need.

Thank you.


*blushes and slinks away*