Why can't people change their denomination? As my profile says, I don't belong to any denomination and I can't answer this question myself.

Recently, there was a question from a Catholic woman having difficulty in her love relationship because her boyfriend  from Jehovah's Witness can't marry her. The main problem  that I suspect is that both of them are not ready to change their denomination. 

Here is the thing I can't understand. What is the problem with changing our denomination? Why don't people want to change their denomination? I am ready to join any denomination if required, let it be Catholic, JW, Seventh Day, Orthodox, I don't mind as long as I can read the Bible and worship Jesus. I obviously have my personal choices. I like to go to a church that uses modern instruments, good music system, good worship songs, good sermons, good Bible study programs and a good and supporting community. For now, I prefer to remain denomination-less but I think I can join any denomination and adhere to their doctrines and ordinances, if their is no other choice available.

Why are people reluctant to change their denomination?

What is the reason why some people cannot change their denomination?

What are the major hindrances in changing the denomination?

What kind of challenges are faced after changing the denomination?
The primary reason why serious Christians cannot switch denominations is because the doctrines surrounding salvation have eternal consequences.

For instance, the Catholic Church clearly teaches that the Eucharist is the source and summit of the Christian faith, and that without a valid transubstantial reception of the Eucharist the human soul will eventually wither away.

On the other hand, most Baptist camps teach and believe that the Eucharist is only a symbolic memorial of the Last Supper, and really has nothing to do with salvific Grace other than a Christ-given ordinance of worship.

...two totally different denominational doctrines...

(I chose these two denominations for no specific anti-ecclesiastical reason other than comparison of doctrine)

Another example is justification by Grace alone through a working faith taught by pre-Reformation churches versus justification by faith alone taught by the majority of Protestant denominations.

On crucially important doctrines such as these, you are either right or wrong. This is why its infinitely and eternally important to find the right denomination (well...at least as close as possible).

Of course there are many other superfulous reasons why people stay where they are, such as familial pressure and tradition.

I really hate focusing on differences rather than what we all have in common, but this question seems to draw lines in the sand. 

It must be said that there will always be overlapping areas of grey, and the Holy Spirit knows what he is doing.