I do think overall that many people put themselves down for being inherently bad at things that they just never learned how to do (like cooking for example). However it is also important to remember that people do have aptitudes for some things and that many people have disabilities and those are real too. Different bodies and different brains will inherently find some things easier than others.
In addition, I want to remind you that there are things that people can be bad at that they have a lot of practice for. Math is a great example of this. At the point where the students who have constantly struggled with math are allowed to stop taking math they usually have had as much or even more practice than the students who find math to be easy. Now, this isn’t as simple as only being due to aptitude. There are also a lot of social pressures and subtle biases coming in (such as the way male students often receive more attention and praise than female students). And one of the biggest factors is the quality of teaching and whether that teaching matches the student’s learning needs and style.