Does Success ride on the back of Uncertainty ? There is no definite answer for this - May be or May not. Then what is Success. It can be answered in many different ways, all answers are co-related to the context. So no point in giving any definition of Success. Just highlight how Success and Uncertainty  rides together as twin horses. 

Success can be said to stand for the following :

•  Step out  to first act.

        Thousands of thoughts   keep passing in everyone's mind  Only a few act upon these thoughts to make it a reality and success.

• Unpredictable things / Unexpected happenings / Uncertain times

       We cannot say or predict or forecast  our own future at all times, whomsoever it may be. Because Nature -Creator / Destiny holds the key.

• Continuous efforts.

       Each and everyone knows that one must keep on doing without stopping irrespective of all obstacles. But alas only some keep going.

• Careful observations.  

       In the present fast paced world, how many really Look, See and then go to execute an idea or plan. Only a few because others do not make

       time to observe Nature and their surroundings.

• Educate Self to achieve success.

       The above is self explanatory.

• Simplicity in doing or executing the task.

       One has to break the task /work given to us into small bits and then proceed to act upon it for desired results.

• Steady mind not wavering and dithering.

Focused approach and not distracted mind because of your surrounding environment is needed.

Uncertainty for everyone  means one and the same, but Success has different meaning and connotations. It differs from person to person and is based on their outlook and perspective in life experiences.