In theory, a project manager should be able to work on any project no matter what field it belongs to. How applicable is that in real life?

In real life companies prefer to hire project managers who have relevent industry experience. There, the project managers from other fields do not get shortlisted.. Though a successful project manager can succeed in managing any type of project, but very rarely I have seen companies choose PMs from other fields..

I totally agree with Salauddin.

Issues here our companies & envirnoment don't let you to take time for learning more about the fields that requires PM. So you need company to provide you with much support & give you a space for moving & creativity.

I think that theory is wrong as one should know the Domain before it can manage things.