Success is a funny old thing to quantify. What for one rider can be a performance worthy of celebration, can for another be a cause of misery. Obviously, different riders should have different goals relative to their standard, but defining success for yourself is about reflecting on what motivates you and gaining an understanding of what to focus on in preparing for your riding.
So think through your individual responses to the following question: Would you ride a bike if you were not achieving good performances?
Now I recognise that some among you (including me) will be asking "What good performances?" but bear with me. For those of you who recognise that you achieve a measure of success on the bike, think about what would happen if your performance levels were 25 per cent less than they currently are? Would you still ride? For some individuals, sports provide opportunities for personal mastery of challenges, for others the social comparison of performance levels against others is a major motivating force. Think about which camp you are in. If personal mastery is your goal then it is likely your motivation levels will be maintained throughout the vagaries of rises and dips in performance levels. If this describes you ensure you are setting good self referenced goals like performances against your PBs or number of miles ridden in a week.
Developing some more outcome orientated goals (eg finishing in the top three) to complement your others would be advisable.
If the social comparison is a major motivator, think hard about recognising the other reasons you ride as you are putting a lot of motivational 'eggs' in a single 'basket'. Poor performances could put at risk you continued motivation in the sport, leading to a vicious cycle of poor performance, lowering motivation, and reducing dedication to training, further reducing performance. It's important to remember the other reason you ride; the camaraderie, the fun and for challenging yourself against you own previous performance levels.
By thinking through your particular approach to your cycling, it might help you reflect on what motivates you and help you get the most out of your cycling.