'Believe In Yourself'
'Know Your Worth'
'You Can Do This'
'Don’t Doubt Yourself... You Got This!'
This advice is so common because, intuitively, we know just how crippling self-doubt can be... as well as how important self-esteem & self-confidence is to achieving what we want in life...
Highly self-confident people are less anxious, less stressed, they better manage their emotions, develop healthier habits & experience better mental health too...
As mentioned, they also have a much easier time building (& maintaining) healthy relationships with others...
Making friends, getting along with co-workers, getting dates, keeping the spark alive in marriages — confidence is key & highly self-confidence people tend to thrive in these area!
(as the saying goes: "confidence is sexy.")
Additionally, self-confidence gives us the much needed strength & self-respect required to also walk away if a relationship, friendship, or business partnership becomes unhealthy or toxic in some way (something which people will lower self-confidence tend to struggle with too!)
In work, it's the same story...
Highly self-confident are statistically more likely to get promotions (leading to more income, power, responsibility, & often, more freedom & autonomy too!)...
This is, in large part, because confident people make better decisions, are more assertive, more resilient in the face of challenges or obstacles, are more creative & in general, perform better at what they do (even under lots of pressure!)
(research on athletes, actors & musicians specifically shows people are more likely to perform up to their potential when they have high levels of confidence).
Confident people are also more motivated (as "believing in yourself" is a huge part of motivation equation), as well as generally more energetic & enthusiastic!
The other reason is that people with higher self-confidence tend to be more charismatic too & better at influencing others...
This includes motivating & persuading other people, as well as selling their ideas, their vision for the future, or their products / services (which also makes them better at sales, negotiation, as well as in leadership positions).
Finally (& perhaps, most importantly) they are happier & free to live their life more authentically...
"Authenticity" is a bit part of what makes confidence, but it's also an end-result of confidence too...
As self-confidence grows, you don't feel need to "people-please" all the time, buy into "peer pressure", or pretend to be someone you're not just to "fit in"...
(thanks to this, confident people are also a lot less likely to be manipulated, or controlled by others, in any way!)
And yes, many studies done over many decades prove that self-confidence has a strong relation to self-reported happiness...
Those with higher self-confidence report to be happier & more satisfied with their life than those with lower self-confidence...
Of course, we know this intuitively...
In fact, we often express this...
We'll say (or at least, think) things like: