Not everyone is born on the same day or at the same time. You experience things differently. The way you learn something is also not the same. But, people will compare everyone to someone who they think is dominant, or aspire to be.
So, you can find very few people who are happy and satisfied. Everyone knows most of the things, but very few people follow. For example, parents may compare their kids with someone else’s kids, but deep down they also know that it is wrong or there are more parameters to consider. But, they don’t because it takes effort to think and act in the right way.
Everyone doesn’t get everything at the same age. To some people, it takes a longer period of time and to some people very less period of time to get what they really want.