The hangover one gets after attending a very awesome Coldplay concert the night before. Due mostly to reminiscing about the high pitched voice of Chris Martin and the awesome instrumental backup he's provided with.
People who have Coldplay hangovers will usually stay at home the day after the concert listening to their music on repeat and posting statuses about how awesome the concert was on social networking sites such as Facebook.
"Hey man, do you wanna go to that party on the 1st?"
"Nah, I'm sorry but I'm pretty sure I'm going to have a Coldplay hangover from their New Year's Eve concert."
"Aw man, I'm going to that concert too and I completely forgot about it. Looks like I'm going to call and cancel for the party."