IN the UK we don't vaccinate against chicken pox and we do actively encourage our children to get it at a young age. Not chicken pox lollipops as have been on the net, but we do let our children mingle when they have it.
The varicella zoster virus that causes chicken pox is normally caught in childhood, manifesting as chicken pox, it's highly contagious and can be uncomfortable, but is usually harmless. You can catch chicken pox more than once, which most likely occurs if you didn't have it too badly the first time.
After chicken pox clears up the virus remains dormant in the body and anytime in later life it can reactivate causing shingles. This is usually when you're an adult, most commonly over 40 and if you're run down or have been unwell.
You cannot catch shingles, you only get it if you've had chicken pox. However, you can catch chicken pox from someone suffering with shingles.
My children had chicken pox together, my daughter was 3 and my son 4 months. I have some great pictures of them all smiley and spotty. It was a worrying time as other babies in out area died through complications with chicken pox when the spots affected their internal organs. Thankfully my two were fine and apart from a bit of itching they came through it really well
I go chicken pox at age 18. I was working in a DIY store and a child with chicken pox threw up over my checkout. I had to clear it up and contracted the virus. I lost a job opportunity because of it because I was too ill to make the second interview. Being older I was more than aware of where all the spots were and I was really ill with it.