I never have tried a PB&J sandwich, but I have a feeling I would really hate it. I do like jelly on a sandwich, but never been too fond of peanut butter. It's not too popular in the UK.
Why eat peanut butter when you can eat Marmite instead?
The yanks may do many things wrong (so many,
many things), including calling jam 'jelly', but peanut butter is the bomb,
especially with marmite.
Hell, if you want to be lazy, they even make it premixed:
Although making it yourself is better.
Regardless of whether you love marmite or are a total mong, there's loads of peanut butter in Great British shops, has been my entire life, and due to it's health benefits there's been dozens of new brands popping up over the last decade. That includes 100% peanut butter, which is a bit bland tasting, but incredibly good for you, since it's the fats that bind the oils in that are bad for your heart and really make you a lard arse.
I do wonder though, do Americans call it 'natural' peanut butter because it's not, as it is here in Great Britain, actually just 100% peanut butter, and instead still contains all the dodgy additives, preservatives and stabilisers that meant we had to decontamination all our equipment, back when I used to work in a food testing lab, whenever we got imported food from the US in to test?
Also how is anyone so cack handed as to not be able to gently stir a jar properly? Surely if you can't do that, you really shouldn't be handling knives.