Frustration.
Everyone is so worried that people will think they are a bad mom if they admit to being frustrated with a crying baby.
The nurses at the hospital told me with my first child that it is normal. Your hormones are out of balance, you can't sleep properly, you have anxiety over doing something wrong and you have confidence issues over not knowing why the baby is crying.
Most women are given the gift of conception but that doesn't meaning learning what to do is inherent.
Please remember to give yourself time to get to know your baby. Go through the usual issues, hunger, diaper change, gas etc. Once you find the reason you will learn to hear the difference in cries.
All of this came about because of shaken baby syndrome. People get frustrated that they can't figure out why the baby is crying so they shake them, causing serious lifelong injuries and death. No one wants to be responsible for something so horrific and PREVENTABLE!
If your baby is crying and you have checked the diaper and tried to offer comfort etc and he/she still cries you may feel frustrated. It is perfectly acceptable to put baby in a SAFE PLACE. The crib, stroller, car seat, swing etc and give yourself 5 minutes to clear your head. Walk away. Fold a small load of laundry. Stand on your porch, stoop, deck etc and just breathe. Giving yourself a few minutes to calm down may save a lot of grief and heartbreak. It also clears your mind and you can calmly try to find the problem and soothe your baby.
Do not be afraid to ask questions. Do not be afraid to ask a friend or relative for help. Just please, PLEASE! DO NOT shake your baby or take frustrations out on them. Remember, they are only crying because they can't tell you what's wrong.