It's a phrase I use several times a day like every other college student, but it means something different when I use it.
"I'm tired." means I spent my night tossing and turning from pain breaking through my medications. It means that even though I took a fair amount of pain medication and went to bed at midnight, I only really slept about 2 or 3 hours at most. It means that I had to change my body position every 30 minutes because of the ache in my hips, back, knees, and even neck becomes too much. It means I spent most of the night uncomfortable and in pain, trying to rest so I can get up in the morning.
"I'm tired." means that when I finally got out of bed I couldn't stand up straight because my back hurt so bad and my hip flexors were too tight. It means I see a shot in my leg in the future because of the pain level I woke up with. It means that doing my hair in anything but a side braid is too much work. The phrase signifies that my morning routine is going to involve several breaks of sitting down or moving slowly. It means I'll probably be late to physics again.
"I'm tired." means that I plan a time to nap during the day so I can work on homework later or make it to that involvement meeting. It means I'll need to rest in bed instead of being social upstairs with my friends in their room. That I need to take time for myself so that I don't end up bed ridden for too long. It means I have to lay down so that I can go try to make it through this concert later.
"I'm tired." means that I don't want to eat, I don't want to go out, I don't want to do anything but watch a movie. It means I don't even have the energy to hold up a book and read, much less take a shower. It means I absolutely need that handicap placard if we run to target and I must use that wheel chair around the store. It means that walking to and from the gym too quickly brings tears to my eyes.
"I'm tired." is a phrase that I use all day long. It's a phrase that every student my age uses at the very least once a day. But, for me, the phrase runs deeper than just because I was up late studying for my biochem exam, it means that I can't do the same things as you. What "I'm tired." really means to me is "I can't.".