This is a cautionary piece of advice for any couples where one member of the couple is about to go on a significant experiential voyage and leaving the other partner out.
I have two examples to offer. I have many more examples from my personal experience.
In the first instance I watched a number of stable happy couples where one member of the couple went to a two day or week long training session in New Age ideology. One was the Earhart training seminar, EST and the other was a copy of EST. Almost invariably, within months after one partner went to the new age training program that significantly influenced their view of the world, the partners split up.
I have also watched the identical result occur where one person went to live for a month or so in another country, often to study or develop their skills. I have seen this occur for trips to Japan, Italy and Israel. One partner comes back home and within a short time the couple has dissolved their relationship.
I think the reason is clear. The experience was so significant in the personality of one partner that the former comfortable arrangement was disrupted.
My observation is straightforward: if your partner is about to embark on some adventure or experience that is likely to have a significant effect on his/her view of the world, you should expect serious problems in your relationship on his/her return.
There are exceptions. But be cautious.