Answer the question about text:

So Mike told the kids that they were going to be on their own for a few hours . I went back to my hotel to change into evening clothes but ended up reading Steve Brust 's Jheggala and then back to the Sheraton at close to midnight . I ended up hanging out a bit at the Australia Victory party in the basement which closed around 1AM and then back up to the Reno in 2011 party which was not as entertaining as the previous evening . I went back to the Hotel by something like 4:30 .

Why will the narrator be tired the next morning ?
They partied late .