Progression is the name of the game, if you aren't progressing you need to evaluate your training and see whats not up to par. This is the time to be brutally honest with yourself, have you actually got stronger, leaner or fitter in the last year ? Or have you just been spinning your wheels.
If like many, you haven't actually made any notable gains in a while, the reason is most likely up to two factors :
1. You have no focus. You flip flop from program to program and don't really know what your purpose is when you go to the gym. For once stick to a program for the whole duration, or set a goal - any goal that will focus you. You don't have to compete, just setting a goal will answer all your questions in the gym about what you need to do. It could be to run a mile in under 5min, bench 50 pounds more, drop 3 inches on your waist or complete an ironman - just make a plan - and stick to it!
2. You don't train hard enough. Even if you think you train super hard, you most likely don't. Fact is it takes a lot of hard work to reach your goals, you will have to be out of your comfort zone most of the time. Comparing yourself to others isn't an indication either, 95% of people in commercial gyms dont train anywhere near hard enough to get real results, so you better be the hardest worker in your gym at the very least! Go to a 'hardcore' gym, or a place where lots of serious athletes train and watch how hard they work, now aim to match that. The US Navy Seals have a saying - when your mind thinks you are done, your body is really only 40% there. Keep going. You can always push harder.