However it's worth noting that some people who get chicken pox only get a few spots, which might not be identified as chicken pox at the time. So while (of course) Sqad is 100% correct, it's still possible that someone who never knew that they've had chicken pox (because the symptoms were so mild) could go on to have shingles.
A friend of mine was totally unaware that he'd ever had chicken pox until he was laid low by shingles (with that diagnosis confirmed by his doctor).