Why is it easier to come back?

So after shifting and becoming aware of the other reality why is easier to shift back here?

Many people may think "well because there is no doubt you have shifted so now you fully believe and it becomes easier". But then why do people struggle to shift again to that DR?

I think this question is the reason many people are scared of shifting because they think they will get stuck and struggle to shift back herr as much as shifting there.