Question

why is it necessary to set our goals realistic?

Answer 1

Reality is something that can't 's be ignored.
Setting your goals and acknowledging reality
is a perfect balance to pursue towards your goal.

Answer 2

Answer:

Setting realistic goals is important because it keeps an individual's motivation up. An individual who sets up unrealistic goals is more likely to become discourage through the process and is therefore more likely to give up on the goal. By setting realistic goals, an individual can maintain motivation and stick to established timelines, culminating in the successful completion of a goal. 

Also, Setting goals is important no matter what you are trying to achieve. There are a range of different goal levels, but there are a few criteria your goals need to meet in order to be useful. One of these is that your goals should be realistic.