In fact, children are usually more focused on the fun and excitement
at hand than any of the crowds and people around them. That is
often why children get abducted easily. They are not aware of
the people and dangers lurking near them.

When people get older they become somewhat less tolerant
of confining situations and large noisy crowds of people.

This is most likely just a symptom of maturity and your desire not
to put yourself into that situation. However, if you experience
extreme anxiety or any feelings of panic I would suggest
you see a specialist simply to evaluate if more is at
hand than normal requirements of personal space.