Understanding our emotions, tolerating them, and expressing them appropriately is a skill. It's both a learned and a practiced skill. We first learn this skill during childhood. Just like we learn how to use the potty, self-soothe, ride a snowboard, and tie our shoes, we also learn how to be emotionally intelligent. Mom/Dad/Guardian teach us how to become conscious of our feelings, how to tolerate them, and express them appropriately.
When we experience an emotion, mom/dad/guardian help us to identify that feeling. "Oh you're crying right now because you're tired", or "You're feeling angry because you can't play with that toy right now". And then how to handle, be with or express that feeling. "I know you're sad, I'm staying with you, I'm here" or "I know you're tired, it's time to go to sleep" or "I know you're angry, it's alright to feel angry, but it's not alright to hit". Over time, the child then learns how to do this for him or herself, just like they learn to recognize the signs that they need to use the potty. The child learns how to identify their emotional state and then communicate it accordingly.
The foundation for emotional intelligence is consciousness. A parent/guardian has to become conscious of the child's experience and be able to identify it for him or her. Likewise, as a adults, we have to become conscious of our own emotional world. The first step is attuning to what we are actually experiencing inside.
You can LEARN and practice emotional consciousness now, regardless of whether or not you had great emotional training as a child. It's important to do so because pretty much Everything (social, familial and romantic relationships, physical health, ability to hold a job, academics/learning ability) is built upon the foundation of emotional intelligence.
As I said at the beginning emotional consciousness is both a learned and a practiced skill. To begin increasing your emotional consciousness check in with yourself a few times throughout your day and take your emotional temperature:
~At work especially after a particularly challenging phone call or meeting. Sit quietly at your desk and just ask out loud, just like a parent might help a child- what are you feeling right now? are you angry? are you sad? are you nervous? are you happy?
~Become conscious and then just like a loving parent to a child- help yourself to express it appropriately. If you're tired, find a way to get yourself some rest. If you're angry, talk to yourself about it- listen like a loving parent- no judging, no changing it- just acceptance. Then decide, from this conscious place how you wish to handle your situation.
~If you're not able to identify your emotional state, try identifying how your body feels. Are there any physical pains? What sensations are you having? Any tingling or numbness? Spend time becoming aware of and describing any sensations or lack of sensation to yourself. The body is a great doorway to our emotional states- becoming conscious of body sensations will ground you to where you are at this moment.
When you're conscious and attuned, you're much more likely to experience successful relationships/job satisfaction etc. If you don't know what you're feeling- and you just keep pushing along- it will get expressed regardless, just maybe not in the way you would have chosen- had you stopped to listen, just like a loving parent to a child.