I was inches from applying in like '01 or '02. I did a little more digging because the reality of being an astronaut isn't much like the dream.
Mary Roach has since written a spectacular book that's basically "everything you always wanted to know about being an astronaut but were afraid to ask." She's got an entire chapter on pooping in space, for example. In it, she goes into great detail about the tests, qualifications and selection processes used by Roskosmos, NASA, the ESA and JASA. Spoiler alert: it's a total grind and a fraction of a percent who qualify will actually be accepted. Of those accepted, a fraction will actually get to space.
She interviewed one of the guys who did some repair on the Hubble, if I recall. He summed it up as saying that he'd spent a lifetime training for a four hour job.
It was kinda stark for me; I mean, one of my mom's best friends (and my piano teacher in high school!) was this guy's sister. He'd show up at our classes pretty often growing up. Listening to him, being an astronaut was kind of like being a taxi driver. You went up into space and did stuff like, all the time.
BTW - they're not hiring at the moment. Back in 2001 or so I printed out their 5-page application and even filled it out. I just never mailed it in.