Paranoia about my system..

I recently installed Ubuntu and when the setup completes it will ask for you to restart your system. Well for some reason it would not, I clicked on the Restart now button and it went to a blank screen with two lines of text one said something about, "module cache". But yeah Ubuntu would not restart, I waited for about 20 mins and still, it was on the same screen. So I held the power button on my pc to turn it off that was the only way, it was frozen there. I then turned my pc back on and it works like a charm like nothing happened no system error popped up or anything. Should I worry about that? I know that you're supposed to restart after installing for a reason, I just hope I didn't break anything. Let me know what you fellow Ubuntu lovers think. Thanks!