You can tell the difference right away, some people feel like they’re more genuine, more spontaneous.
When they say “congratulations” they look into your eyes, shake firmly your hand and smile from side to side.

They’re not lying, they are true to their feelings and don’t have blocks for them.

It might seem like something you can’t “learn”, but you can.
Start by not accepting compromises, not with others, with yourself.
Express your range of good emotions always when they show up.
Don’t limit them, be happy for the other people successes instead of being envious of them.

Celebrate joy and playfulness and live with the struggle.
The fact that getting to learn things like this requires time and effort and failure, constant failure.