Are you a 'Just In Case' person? Do you carry around pain killers 'just in case' you get a headache? Do you want a Swiss Army knife for your key chain...not just because they are SO classically cool...but also because you want one 'just in case'? And possibly a tiny LED light? ..because who knows? And a rape whistle. Just In Case.
Just In Case items aren't as much practical as speculative. While it's practical to order extra toilet paper...it's speculative to have certain other items on hand...Just In Case. It's like, a lifestyle...like you have to have on hand extra of that amazing Curry Ketchup...Just In Case! you run out and/or it's heaven forbid...discontinued!