This could be for a number of reasons:
Reason One
You're not as small as you were last time you went on holiday. There's a number of smaller reasons for this; you ate too much, you don't do enough exercise, or it was such a long time ago that you've actually, God forbid it, grown. It's odd to think that that can still happen, no matter what age you are. People swear that they have stopped growing, but this does not explain why a pair of perfectly good quality tights are suddenly under your rib cage instead of around your hips. Even as we get older, we continue to grow, whether it's because we change our routines our simply because we hit that age when we start to shrink.
Reason Two
This favourite item of clothing has been put in the wash at a temperature it shouldn't have, and has either shrunk or grown. This is quite common and extremely annoying.
Reason Three
This doesn't really have anything to do with size, but a small child or pet may have gotten a hold of your clothes and ripped a massive hole in them, rendering you incapable of wearing the clothing without showing off an inappropriate amount of flesh. Of course, there are some people who would wear it even if it had been ripped in half and it would be better to just wear underwear. You know who I'm talking about.
Reason Four
To be quite honest, I'm completely running out of reasons. It's something a writer should never admit to, but hey maybe it'll give me a sense of normality as a human being. Anyway, reason four is that karma is a bitch and if you do something to upset it, it'll come right back and bite you on the ass. By making your favourite clothes too small.
