Although we all have our own weird body issues, we're mostly fine. Really, we are - as long as we keep reasonably active, eat food that isn't entirely plastic, and apply at least one basic grooming tool to ourselves every few days. Until we hit our late twenties and early thirties, that is. Then all bets are off.
Let up on your exercise for just one day, and your body completely deflates. All of your muscle mass is immediately replaced with gel. Eat something indulgent and you fall into a weeks-long state of weakness that culminates in a face-to-face encounter with the spectre of your impending death. Skip a shower and your grubby skin becomes a permanent cosplay of a Mad Max character.
There are many signs of your shitty body's imminent failure. None of them are avoidable. It's best to prepare yourself now so this stuff won't come as a shock.
Observe your forearms. The hair has become longer, coarser, and more plentiful. Looks like a closeup of one of Robin Williams' knuckles after he punched a wig factory. When you step out of the shower, it seems as though you have just finished unclogging a mammoth's toilet with your bare hands.
Now try to contort your weak body into a new position, getting a good look at the back of your upper arms. Scary, right? Those ten or twelve random hairs just chilling out, darker than any other part of your body. Note how they contrast with the color of your saggy skin in that particular area, a patch of paleness that must have been transplanted from an albino California raisin when you weren't looking.
Feel your buttcheeks. Weird, you don't remember taking off your pants and underwear then sitting on a carpet for three days, but there it is. The texture is unmistakable. The spot where your ass meets your upper leg was once a firm curve. Now it's basically just a big flabby earlobe.
Your face... ugh. It was once a strong, the features prominent. Now it's distressingly malleable. When the skin is pulled it just sort of stays there. Sleep too much on one side of your face, and it takes a dozen hours after waking for you to regain the ability to blink.
Your eyes hurt. Everything causes them pain. Work in front of a monitor for an hour and they feel as if they have been blasted with sand. Close them for a nap and they become blurry and unfocused for approximately the rest of your life. Read a few pages of a book and they get tired. You press on, closing one eye to rest it until eventually the other one starts to wobble and cry. That's when you know it's time to sleep. Except you can never sleep again, because all you can think about is death and all the things you should have done.
Remember when your veins were kind of cool? You had to look really hard for them on your wrists, but when you found the weird little things you could see them moving slightly with your pulse and it was amazing. Now they are horrifying reminders of the crude machine that is your body. Sprawling ropey strands stretch across your forearms and wrists. They push against the translucent skin of your palms and between your fingers. You are essentially a walking display case for your veins. People secretly call you Vein Person, as your blood delivery system is basically all that anyone can see when they look at your fucked up non-face and lumpy, stupid body.
Even your smell is getting weird. No matter how much you scrub and deoderize, no matter how often you toss out old clothes for new, the unmistakable new scent lingers. You never smelled like this before, yet it's familiar somehow. If you could just place it... Ah! There it is. Milk gone sour. That's it, the wafting aroma of decay.
Waking up from a sleep used to be refreshing. Every molecule in your body was a wound spring, set to fling you effortlessly through another day. If you took a few moments to enjoy the morning, you might have let a patch of sunlight warm your face as you pulled the sheets tight, nestling your head against a pillow that was neither too firm or too fluffy. Now you wake up and your bed is much smaller. The silk that you lay upon is cold and chintzy. You don't even have a sheet or a blanket. Your pillow is a frilly thing with far too much lace. Everything is dark. Far too dark. You reach a veiny hand out and encounter some sort of paneling less than a foot away from your face. Attempting to roll over does no good. The box is too small for that.