Nowadays, there’s probably nothing more important to digital photography than those little plastic things called memory cards. Except for maybe the camera itself. It doesn’t really matter what kind of card you use. Without one, your camera and your fully charged battery don’t matter. You just won’t take any shots.
I never had a card fail on me. I never actually forgot to bring a card, but ever since my 64 GB SD card failed outside of the camera, and for that matter ever since I’m stuck to a 16 GB card, I’ve run into this issue at least twice: A full card. The last time that happened was yesterday when I wanted to shoot the ADAC Rallye Niedersachsen near my hometown. I had forgotten to backup and clear the pictures I shot at that airfield fest last weekend.
Even if your card doesn’t fail or isn’t full, you might forget it in your computer after syncing pictures to Lightroom or whatever software you use.
What I’m trying to get to is, that you should always put a spare memory card, n0 matter what. Even if you’re shooting just for fun, there’s no bigger downer than to not being able to shoot at all. So for your own sake, always put a spare card in your bag. Maybe you can even help out a fellow photographer with a cheap SD card.