What does it feel like to achieve your dreams?

When you achieve a goal, especially if it was very important to you, your happiness levels will go up almost instantly.

If the goal achieved was very important, your happiness set point is going to change. This means that your overall long term happiness levels are going to be higher than they were before unless something changes the set point again. 

When you achieve a goal that matters to you, your self-confidence will increase. The self-confidence boost is going to depend on the importance of this goal to you.

When you achieve your big life goals, your self-confidence might increase so much that you might develop some arrogance. Not all people who achieve their life goals become arrogant.

When you achieve your important life goals, your overall energy levels will increase. You will become more motivated and your overall excitement about life is going to increase. (See Why should goals be measurable?)

If the goals you achieved were big, your belief system might change and you might start to think that you can achieve anything in life. This level of confidence will remain there as long as your beliefs don't change again. 

After reaching your life goals, you might start to think about the next steps and so you might develop some even bigger goals. Your increased level of confidence will make you more likely to set higher goals.

As a result of the belief change that will happen to you after reaching your important goals, you might become very optimistic. You will start seeing opportunities instead of obstacles as a result of this optimism. (See Why are some people very optimistic?)

Motivation happens when a person believes in themselves. After achieving your big dreams, you will develop many positive beliefs about yourself. Those beliefs will make you very motivated to achieve more goals since you will believe that you can reach any goal.

After achieving big goals, you are probably going to feel proud of yourself. You might start to share your success story with others as a result of feeling proud.

The pain you experienced on your way to reach such goals is probably going to go away. The memories of the difficulties will remain, but the emotional part associated with them will fade.