How does one who is making the effort to learn more about themselves and make improvements to lead a happier more centered life, coexist with those who do not wish to do the same?

There are different ideas and lists of what key core human needs are. One of these theories or lists identify “growth” as a fundamental human need. This is the idea that all human beings have a “need” for personal development and continued growth. The challenge is that some people place that need much higher on the list than others do. Some clearly have it on the bottom of the list and it can even seem some have no drive or motivation for personal development or growth. This is most difficult when these are those closest to us, including family and friends. 
I find that those who are happiest in life, make it a personal goal and pursuit to always be learning, growing, and becoming the best version of themselves they can be. This personal development can be from a variety of areas such as mental health, physical health, and spiritual development. Trying to figure out how to “coexist” with those that do not share our passion for growth and personal development can be challenging. 
Those who do not share your interest and passion on your personal development journey may fall into two possible categories. One, they can be somewhat “neutral”, meaning they can let you “do your thing” but not be actively helpful. Nor are they actively trying to discourage you or are being “dream killers”. The second group may actually be very discouraging and criticize your goals and interests to become the best version of yourself. They are “dream killers”. 
Here are a few things to consider: 

1. Do your best to stay focused on your goals and who you want to become and don’t let anybody get in your way! Know your “why” and remind yourself often of this why. Friedrich Nietzsche stated, "He who has a WHY to live can bear almost any HOW.” I love this quote!
2. Set clearly defined goals on what you what to learn and how you want to grow in the near future. 
3. If you have people who are actively criticizing you for trying to be healthier and happier, you may have to limit or eliminate your contact with them. Obviously, if it’s family, eliminating them from your life is probably not the right thing to do. If it’s a friend or even significant other, you may have to disconnect from them. If they are in the category of not being able to completely disconnect such as family, you may consider having an honest conversation with them and ask them to not say discouraging things about your journey. This unfortunately may fall on def ears. 
4. Finally, stay close and connected to those who do support you and who also have similar aspirations and views on personal development and growth. You all can motivate each other. Develop a “power team” of sorts of like minded people. This can counter the naysayers and dream killers.  
5. Understand your personality.  Some personalities struggle more with taking other’s criticisms personally and become deeply hurt by them. A good personal development goal for this personality trait is to learn how to not take things as personally as you do. I know this is easier said than done, but it is possible!