Thats good if you a mediocre in everything as it opens up a great opportunity to try all the things that you believe you are mediocre at, and the shortlist 3 things that you did well out of all things listed.
Now work again upon those 3 things to find out the no 1 activity or skill which you like the most or interest you the most.
Now work upon this skill and try to make it your USP.
List 10 things you are mediocre at, do each activity for 3 days each.
Self assess which three amused you the most.
Out of those three, do each for 5 days and find the best in you.
Use motivation from internet and YouTube for that activity.
This will do two good things for you, one you will gain lot of knowledge for all 10 listed activity if you do this exercise religiously. Second, you will get a chance to find the best in you.
This can be done by anyone and students can consider this no 1 activity for themselves during vacations.
Seek help of parents and friends to make it more interesting.
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