LPT: Wait 3-6 months after making a lifestyle change before telling anyone about it
I'm going to use some examples here, but this can be a useful tip for how not to be an asshole for everyone. If you have decided to attempt keto/become an atheist/start lifting/discover feminism/not to have kids, I would suggest giving yourself some time before making an attempt to announce it to your family and friends. These are the people we tend to alienate the most because they are closest to us. And if you are a minor who is dependent upon your parents, I suggest seriously considering not making an announcement at all unless you are being physically or emotionally harmed.
I know when you discover something you are suddenly passionate about, you want to tell the world about it. It's natural to want so badly to share with those closest to you this exciting new discovery you have made. It has changed your life, and there is a whole new world out there and you want to recruit others to share in it as well because you have found the key to happiness.
I suggest taking some time to learn about this new area you have discovered before you start telling everyone else why they are suddenly wrong or how they are smothering and disrespecting you. Read as much as you can, live your lifestyle for a few months, and see if it becomes just another thing you do or think rather than something you are. Ask yourself why what everyone else is doing is suddenly wrong, what you have to gain by sharing this information about yourself, and if you are bringing something positive to the conversation rather than trying to bring everyone else down.
We see a lot of rants in our favorite threads, and we can identify. "Everyone is stupid but us. Why don't they get it? Why aren't they listening to me?" Your approach has a lot to do with how people perceive you, and how they will perceive what it is you are representing.