Unix commands, don't get them wrong

Okay, I'm sitting there minding my own business and suddenly the PC goes bleepbeebeeebebeb.

Okay, I may slightly be doing a Ellen Feist on you, but its exactly how I feel?
Whats the difference between */ and /* ? a whole server!!!

Okay, the command I tried was this:

chmod 0644 */ -R

Which should have made all files in the directory I was in to 644 (Read and writeable by owner, but only readable by others). But as I was typing too fast I did this:

chmod 0644 /* -R

Which doesn't do the same command, if I'm in /home/user/public_html, it doesn't run the command from public_html it runs it from the root, right at the top, like setting all your C:/ to permission denied (For you XP readers).

Its just those few seconds while you wait for it to run, then reload it through your head and get that sickly feeling as you have just realised what you have done, you hit Ctrl +X as hard as you can but you know the damage is done

One server, over 300 users and I have just successfully written off the server, boy this day could get better :(