Perfect replies from Don and Chris, depressing trigger, gently and easily sliding the needle into position is critical. When cleaning I always dis-assemble the front bits, then either push the needle forward for wiping residue off before rearward removal, or even better just remove needle in forward motion.
When I get a new needle, if it's marked with grooves to identify size I take fine sandpaper, double it over, insert into the grooves, then lightly sand both sides of each groove to smooth the top edges, then sand all around the top surface of the grooves, plus the machined end of the needle.. That prevents any roughness from the groove machining causing damage to the needle bearing, as the needle travels through the body in forward removal, or backward installation.
The needles are actually quite durable, but really do require rather gentle handling and storage, when not in use. If you tend to work really close to your work, as in camo painting, perhaps you could be pranging the tip on the surface you're painting, and just not be aware of it. Best of luck with preventing it in future.
Patrick