Competitiveness

There is a big difference if you are doing things alone or in the company of others, most people are physically capable of so much more when they have somebody to compare to, especially if that somebody is better than them.

This drive to be better than you fellow man is probably greatly responsible for many of the good and bad things from history. The overwhelming urge to prove yourself in the eyes of others, to beat them and feed your self-esteem.

On the other hand you have people who cave in under this pressure of trying to prove themselves and freeze when in contact with other people, their brain desperately locking up, effectively achieving just the opposite of what it wants, followed by a vicious cycle of self-recriminations and accusations.

It is very hard to ignore the urge to do better when other people are around, and people who fight against it usually overdo it, intentionally being much worse to other people than they are by themselves - this is especially noticable in puberty.

There is also a startling difference if you are in the company of one person who you know well or in the company of many who you do not know, or know only superficially. There are so many masks people have for various configurations of companies and settings that there is no wonder that sometimes the masks collide, leaving one of the two (or three) different beneficiaries of different masks wondering if they really know the person behind the mask, now that they behaved so differently.

The masks are mostly of course used to make an impression on others, to convince them that we really are something (usually something they appreciate) and thus they should value us more. It is really hard to wear your heart on a sleeve, when you have many hearts and many sleeves for many different occasions.

People who are always their true selves are usually hated or ultra-famous, depends on how much nervous energy they have coursing through their asocial minds.