Failing as a photographer can mean different things to different people. Most would think that you fail because you cannot make a living at it or you tried but failed. When I talk about failing, it's things like forgetting your memory cards, charging your batteries, etc.
How many of us have gone out to shoot only to realize you forgot a key element. Pulled your memory card from the camera to download you photos and forgot to put it back. I have done this one personally but I always keep 4 other cards in my camera bag. However, keeping 1 or 2 in the glove compartment or console in your card would be a good idea in case this happens.
What about not charging your battery? When I first got into photography, I only had 1 battery and if it went dead I was done taking photos. I soon purchased another one but realized 2 was not enough. Eventually I ended up with 6 batteries and always keep them in my bag.
Forgot my remote shutter on a shoot. That really sucks when you want to do long exposure. A camera cannot do more than 30 second exposure without a remote shutter. You can take a lot of photos then stack them in Photoshop but that takes a long time.
That one that really hurts is when you catch your filter holder on something and you watch the new Haida Clear night filter come off the camera and land on the rocks. I least I used it for 1.5 weeks before it broke.
Failing is something we all go through and if you haven't, you will. Take it in stride and hope you are with others that have the equipment you forgot. If not, make sure you have extras of all the small stuff. Just get out and fill the frame with what you like unless the smoke in the air is so bad that nothing will turn out. That is what we are dealing with in Seattle right now.