You are yet to realize what you are?
This is it!
No, you cannot do everything. You are limited as long you have responsibilities that you needs to fulfill, desires that needs to be satisfied and duties that you must attend to.
You are not free physically, you are bound by your surrounding circumstances as long as you seek the pleasure of happiness of your ppl and you.
Yes, Everyone is different. It depends on the circumstances and environment that you were born in that determines who you become . Not everyone can do the same work in same time or with same inputs. Some may need extra inputs to do some work for which others may easily do.
Human being is limited as long as he enjoys being Human.