I was also a bit of a prolific shoplifter, I think with allot of teens it's a stupid daring type of faze, I know it was for me. Here's my story...
It was mainly in my local Woolworth's (R.I.P), which was an easy target as it had little to no CCTV and most of the staff were in their late teens/early twenties and just stood around at the checkouts and unpacked boxes which were at the entrance to one side of the store, which meant free pickings down the back isles of the shop with no CCTV. Most of the stuff I stole was food and drink basically, not becuase I wanted to steal it but pretty much becuase me and my mates at the time just used it as a free pitstop when we were in town all day as kids, as cheeky as that sounds...
I started out around age 10 back in 2008 just taking handfuls of the pick & mix and the odd chocolate bar with school mates, then by 11 a year later I (and friends) moved on to the more bigger "risky" stuff, like putting 2 whole cans of coke in waist band, taking pairs of sunglasses off the rack and walking out, stealing packs of playing cards (didn't even need or use them!), I once stole a DVD, and that sort of thing... Then after about 12-18 months of this me and my mates just started taking the p*ss, like literally walking into Woolworth's with an empty back pack on, and just stealing ANYTHING that A. We could conceal and B. Wasn't alarm tagged.
After all of that between 2008-10 the want to go and shoplift stuff kind of wore off, a few of my mates I think got sussed by their parents so were too scared to do it much anymore, and my mates and I stopped hanging around with one older mate (who was about 14-15) who pretty much influenced us to shoplift.
Last time I went into a store intending to steal something was when I was 14, I went in all cocky becuase of my previous success in doing it, but ended up nearly actually getting caught!... It did s*it me up a bit afterwards and made me really think how petty it was and that my Mum had raised me better then that. (Sorry for the long post!) 