Masturbating once at One [o'clock], twice at Two o'clock, three times at Three o'clock until [twelve] at [Twelve o'clock]. In total 78, good challenge.
Me: I have only ever Consecutively [fapped] 7 times in a single day.
Friend: if you think that is bad, try the 78.
Me: what's that?
Friend: [look at this] page?
Me: my [gosh]
Friend: I know right?
A quick and [discrete] method of informing someone who is about to answer [the phone] that you're "not here." Traditionally, once you've declared your 78 status (simply by saying the number when the phone rings), the person answering is required to inform anyone asking for you that they've not seen you since . In some cases there is [leeway] for alternative responses (as when the person on the other end may be familiar with 78) as long as you are protected from having to take the phone. If everyone in a room calls 78, the last person to call it must answer the phone.
An [override] code is also sometimes used. This is a predetermined year (post-78) that friends can use to override 78 and reach you in an emergency. The correct usage of the override is to tell the person who is answering "You're no help then; I was talkin to him in  (or , or whatever you've picked)"
Jeremy (being the only one left, answers [the phone]): Hello? Greggo? I ain't seen Greggo since '78. Sorry.
78 refers to something [being cool] or awesome.
sometimes referred to as 'page 78'. When used as 'page 78' it refers to calling someone nerdy.
Note: When speaking of 78 one usually makes the [gesture] of pushing up their glasses with their [index finger]. This occurs whether the person wears glasses or not.
Dude! that's 78!
Guy 1: Hey [the answer] to that is on page___
Guy 2: what did you like read the whole [textbook] or something? where's the next answer? page 78?
78 [RPM] Record that is played on a [turntable]. That type of record is very old and most young people today have [probably not] heard of it!
[Some people] still [listen] to [old] 78s.
[the numbers] [represent] a [teabag]
User1: my girlfriend watched her [brother] get a 78
Commonly used as a more [innocent] way of saying "[thot]" or "[slut]"
hey Jordan, did you know Jennifer blew [the science] teacher infront of the class so he would let her play the new [grand theft auto] [game under] the exams, she's kinda a 78