last night as i was closing for work my friend marissa calls me and tells me to come over . As far as i knew it was only her and renee and mario at her apartment , i got there and was getting ready for bed and 4 people bursted in the house with beer . So marissa and everyone got excited and by this time it was about 2:00 am . So everyone ended up drinking and i tried to sleep but mission was not accomplished .
According to the above context, answer the following question.
Why is the narrator feeling groggy the next morning ?


They were up all night drinking .