SIM has 2 meanings
Shoot, it's MondayCensored
Are you currently texting or chatting with Garfield the cat? Because when you receive the acronym SIM in a text or chat message, it often means "shoot, it's Monday."
Of course, Garfield is not the world's only Monday-hater (just the most famous). Anyone who is upset the weekend has already ended may use SIM to mean "shoot, it's Monday," as may anyone who has forgotten it is Monday until just this moment.
SIM! I forgot to take out the trash! And I'm late for work!
|IHM||I hate Mondays|
|Oh snap||Expression of surprise|
|Whoa||Expression of surprise|
|Woah||Expression of surprise|
|AOAS||All of a sudden|
|Facepalm||To place your palm on your face in embarrassment|
|TAC||That ain't cool|
In emails, SIM stands for "subject is message." An email's subject line starts with this acronym when the sender has fit their entire message into the subject line. If you receive an email whose subject starts with SIM, you likely do not need to open it, as it should not contain any body text.
For example, the following SIM emails would likely include no body text:
SIM is similar to the acronym SSIA, which stands for "subject says it all" and may also appear in emails and online forums. Often, when you receive a SIM or SSIA email, there's NNTR.