Refreshing the twitter feed 3 times in a row and nothing new appears
Feeling proud that someone favourited or retweeted your tweet. So much so that if you met someone who'd just finished a marathon, you'd make them feel like they're under achieving
Feeling the need to tell the world someone famous replied to the 100th tweet you sent them... forgetting to mention it just quoted your annoying message and said "people like this..."
Using tweets instead of a direct message or a simple text! Twitter is for telling the whole world something right? So no one cares if you want to get pizza with Kim on Saturday.
Slipping hashtags into everyday life
Quoting famous people
Tweeting about breakfast, lunch and dinner!
Having multiple accounts so you can tweet more and not annoy the same people.
...and many many more. I'll post them when they come to mind