I like steam most of the time, because it is a pretty good system of managing your games. However, the moment something goes wrong, you're forgeted. If you happen to lose internet connection for any apparent reason, you can't play a single game you downloaded from them. Well why not play in offline mode?
<insert link to steam support page here>
Step 1 says you need to be online to go into offline mode.
Who the forget does that. Seriously.