Often we think if someone else can do it    
then we will definitely be able to do the same .. 
I think it's not completely true or completely wrong .. There are a few things or maybe a lot of things someone can do but not easy or even cant do for us , or maybe someone else will be able to do it better than we did .. 
How about you ..? do you want to prove if you can do what others can do .. ? 
SURE YOU CAN ..! ! The sentence is very good for you to always believe , although you may not be better than others but with that sentence you will be able to measure the extent to which limits your ability .. 
I proved a lot of things about it .. sometimes it turns out I get better at doing it . . rare but I  even have much worse outcomes than that I want to emulate .. 
Learning .. never give up .. it will make us better and we will always be one step ahead compared with those who only doing nothing and thinking of himself know everything and can do everything .. 
someone who is dumb but has a willingness to learn is better than someone who feels they does'nt  need to learn ..