Is it me, or...?

This type of question is used to check that something you noticed, saw, read or heard wasn't a figment of your imagination. For instance, if you run into someone you haven't seen in a while and you think they look thinner, you could ask Is it me, or have you lost weight?

It's also used to see if other people agree with you on something you're feeling or perceiving. For instance, if you're in a room with other people, and it feels kind of warm. You want to open a window, but you don't want to speak for everyone. So you ask, Is it me, or is it warm in here? which basically means «It's a bit warm in here, wouldn't you agree?».

Pay attention to the intonation: 

⦿ Is it me, or have you lost weight?

⦿ Is it me, or is it warm in here?

________________________⦿ She's fun. | I always enjoy her company.⦿ got into teaching | began working as a teacher⦿ it suits her perfectly | She's perfect for the job; she has the right personality for that type of work.⦿ Hey | Used to change the subject in middle of a discussion and express a concern or question. Pronounced quickly, with a falling intonation with a nuance of «Now that I think of it, let me call your attention to something else...»⦿ to get a clear shot | This is normally said of something that's easy to shoot — within a clear shooting distance. However, we often use it figuratively when we talk about getting a clear view of something.

Brothers Alex and Nicky say goodbye to their cousin, Amy, after a visit. They hadn't seen each other in two years.

____________

Alex: That was nice. Amy's always been my favorite relative. 

Nicky: Yeah, she's fun.

Alex: And I think it's great that she got into teaching. It suits her perfectly.

Nicky:  Absolutely. Hey, is it me, or does Amy have a tongue piercing?

Alex: I was wondering the same thing, but I couldn't get a clear shot of it. 

⁕ ⁕ ⁕Here, Nicky genuinely doesn't know if he saw what he thinks he saw and is wondering if Alex saw it too. Other expressions that can be used here are Am I seeing things, or... and Is it my imagination, or...