Overall, I think you have to understand your audience and whether he, she or they may see your plans as a rejection/put-down of their own lifestyle and life choices.
I don't talk to my family (meaning parents and other relatives) about the FI plans my husband and I have. I think a big part of it is that it's a generational thing (tied into first sentence above). I'd love to hear MMM's take on this one of these days. I say this as someone who, in her pre-Mustachian days, was convinced to purchase expensive furniture for a studio apartment I bought many years ago. My parents' take on it was that it was what a homeowner is supposed to do and that resorting to Ikea is for college kids or those who just can't afford anything nice or, worse, don't have good taste.
So, without taking a deep breath first and considering if this would actually enhance my life in the long run, I agreed to share the cost of some nice pieces of furniture (even then, it was still out of my budget but they insisted on paying for part of the furniture as a gift). Yes, my apartment looks lovely, but now, years later, I'm renting it out, and when I do sell it, well, I sure hope the buyer likes the furniture enough to take it off my hands. Not only do I want to avoid the cost of a mover to remove these bulky items from the apartment, I have zero desire to pay for storage. In the long run, the removal and storage of the furniture that now, years later, I have no use for, will cost more than it's even worth. The pieces have become a ball and chain and will most likely end up being sold for a fraction of what they're worth, or be picked up by the Salvation Army truck for a tax write off.
All that said, if I admit to my parents today that the furniture wasn't necessary and I should have stuck with Ikea, they would look at me as if I have three heads (and call me very ungrateful). Let's just say I come from people who if they made it to the "Showcase Showdown" section of The Price is Right, they'd be happier to win the home furnishing showcase instead of the travel/car showcase-- why would you want the risk your life and money for a car that isn't as good as what you'd pick out and such and such places are too far/too expensive/probably crime-ridden.
Furniture issues aside, there may be people in your life who believe Mustachism is BS and just some kind of hippy pipe-dream crafted by someone who doesn't want to do things the long and hard way (because of course we're supposed toil to fulfill the correct version of the American dream-- expensive suburb, SUV, two car garage, "good schools" funded by extremely high taxes. If your experience tells you someone will just say you're ridiculous, put down your ideas or just get offended by them, don't say anything. Just focus on yourself and never feel you need to justify.