A lot of successful people are asked this question on several occasions. If you have cracked IAS, people ask how does it feel to become an IAS. Same story goes for successful actors, entrepreneurs, politicians etc. I feel this question is absurd and shows the ignorance of the people asking this question.
Achieving success in any task takes serious effort and achieving same goal may mean different for different persons. It all is dependent on the person and their journey.
Consider the example of climbing a mountain, if a person is fit then they would enjoy the process of climbing a mountain. However, for an unfit person, climbing mountain would be a miserable experience. In the end both will have different stories to tell.
Same thing goes while achieving success in any task. If you are regularly developing habits and skills required to achieve success in any field, your journey to the top will be joyful. However, just wishing for the success and not developing right habits will for sure make you miserable and you will be left wanting in the end even after achieving success. You might even start questioning yourself if you ever wanted to succeed.