How important is Pre-K?

My son just turned 4 in April, and I recently started looking into enrolling him in Pre-K. I've never done the school thing before, and unfortunately, no one told me what a huge process it is. I began calling day-care centers in my area at the end of April, but they all already have waiting lists for Pre-K for the upcoming school year! Also, I didn't realize that he had to have a recent dental record, eye exam, hearing exam, and a million other things. I knew about the immunizations, but that was it. So, needless to say, now I'm waiting for his dentist and doctor appts before I can even register him and start putting him on some of the waiting lists. I have a feeling that he won't get in this year. Next year, he'll be 5 and will start Kindergarten. Would it be bad if he doesn't get in Pre-K. I feel horrible about it, because I know that the more he learns before school, the better off he'll be. Did I screw up?!?
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I would not worry about prek much unless you feel your child is socially behind where he would need extra time with children or has trouble with leaving you . Otherwise you can teach him at home what he needs to know before starting kindergarten. You can check with the school he will be attending next year and they will tell you exactly what he will need to know to begin kindergarten, I know here in TX they have to be able to count to 20, recognize that letters stand for something (A=apple or so on) there shapes, colors and how to correctly spell their first name and ledgibly write it so that the teacher can tell what they are trying for. If you are just concerned about the social aspects of prek you could always do mommy days out or set playdates in your area.
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