I've started seeing this guy... it hasn't been that long and I don't know where it's headed, if anywhere... but right now I like him and enjoy his company.

In a conversation about life and love I told him I don't fall in love quickly but if and when I do I fall deeply and he told me he usually falls hard and fast, hence the 2 ex wives. 
His shortest relationship being a girlfriend of 2 and a half years and the longest was the first wife of 13 years. So naturally, knowing himself and looking at his past... he would like to take take it slow

Well thats a pretty big package so it's not like it's something I'd jump at but I'm not discounting him altogether either... I'd be happy getting to know eachother and just seeing how it goes. That's the way I've always done it, theres either something there and your feelings grow, or there's not and you don't continue with it. I'm not saying that's the right way... what would I know, I'm single..lol  but it's logical to me.... and if it's going well, somewhere along the way you find love. Right?

Being that he is not used to going slow he said he has to be absolutely sure, and we have a long way to go.
A long way to go to what? I asked
"To taking that step where we both let go and fall hopelessly in love with each other... I'm not ready to do that just yet"

I understand with 2 ex wives and 3 kids he would want to be sure before he takes a chance again, so I understand why he would like to take it slow....

What I want to know is how do 2 people getting to know eachother... take it slow?
It's a totally new concept to me... like I said with my past relationships the magic... whatever that is... was either there or it wasn't and I let it unfold.

Take it slow...  what's it even mean?
Does it mean you only see eachother once or twice a week, or that you don't whisper sweet nothings, that you don't give your heart away (how do you stop that if it's where it's drawn anyway) Does it mean seeing eachother but it's not exclusive, or does it mean you don't think about or talk of the future? 

And why does... 'take it slow' make me nervous?
Why does it feel like rejection? Why does it seem to drag up insecutieties I don't understand?
Things were great until he threw that in...lol... I was just being me, conversation ran smoothly, everything was easy... But now.... now I can barely string a sentence together because I'm always thinking about what I'm saying, if it's too much, if it's coming across right, would that sound too forward, would that sound like I don't give a shit,  and omg he must think I've lost the plot.
I went from someone that was getting to know someone to someone that can't put a few words together. Yeah, that's attractive...LOL

Can someone please tell me what take it slow means and how one goes about it while still appearing sane!!