My 3 year old is obsessed with school?

So everyday my 3 year old tells me he's ready to go to school. I tell him every time that he will have to get up everyday and go, mommy wont be there with him and it's a big thing to do. He could go to head start, but really I'm just not ready to send him, the way I look at it he's gotta go to school for 13 years, why start him so early. He will be a late starter due to the fact that he will turn 5 in January so I will probably send him to preschool when he's 4, but I don't think he should go this year. So my question is should I keep him home with me this year or give in a let him go to head start. i'm just afraid he doesn't know what school is and he wont want to go after he starts. He used to go to day care but I lost my job so now he doesn't get to go to anything like that, which makes me think that's why he's so insistent on going to school.