Is a 3-5 second delay normal for a Retina MacBook Pro to wake up from sleep? For 3 days, I now got a new rMBP. I am a first time Mac user.

I had a friend with a MBP and it usually wakes up in a mere second, as soon as he opens the laptop's lid up. However in my Retina MBP, it takes a few seconds (3-5s) to wake up.

Is this normal?
After the rMBP or the MacBook Air are left sleeping for one hour, they enter a deep sleep mode in order to conserve battery.  Traditional Macs without SSDs do not enter this mode, so they might awake from sleep a bit faster.

To answer your question, that is normal behavior.