What I found out in recent couple of years is that people tend to go through particular loop: have some particular aim -> achieve it -> get comfortable -> lose comfort -> find another aim. And this loop continues on and on. Moral of the story: we are always striving for better and higher. No matter how good our situation is, it is always some need of better results.
My personal example:
Five years ago I just wanted to learn English. I was tired of being unable to understand YouTube captions as well as original movie scenes. As a result, I enrolled into accelerated English courses. Great, after a couple of months I could at least get some context from the movies! Yahoo! Bored. And then suddenly - I can prove my English skills by passing an IELTS test and get certification of foreign language knowledge. Sweet! I spent three months preparing for examination and scored band 6. Victory! Bored. But wait, with IELTS I'm able to enroll into foreign college and learn English, plus get some international experience. I went to Australia and was admitted to a college for diploma of Information Technology. Yay! Bored. Wait, with Australian college degree I can enroll into university to get a bachelor degree to become more skilled in area of IT. After passing of examination - enrolled. Done! Bored. University degree was not enough to fit my passion for technology needs, so I needed some real-life experience. I needed to find internships. Secured couple of internships with projects and gained valuable industry connections. Awesome! Bored. Now I need to find an AWESOME place to work to support my strive for learning as well as contribute to projects and be a part of amazing team. I joined the best company I could dream about. Yes! (Not bored yet :) )
As a result, we always seek for an upgrade. We are looking for a new relationships, jobs, projects, places to live etc. It is totally natural to switch and try new things. These changes are always very hard to implement, since on most of the stages we are getting too comfortable with what we have at the moment. But leaving a comfort zone is the only way to check if there is something even better out there. What if not? You gain experience, and no regrets should exist. Period. The biggest mistake is not to try to change things, to be afraid of it.
Make your choice ;)