It's highly likely that you're neighbors aren't preppers because a high percentage of the population is definitely not prepared for most or all SHTF scenarios imaginable. You will be lucky to know even one neighbor who has even a vague plan for what to do in a disaster situation.
With this in mind, once an emergency that affects the whole community occurs, you have two options. First, you can "go gray," or act like you are one of the unprepared. This has its advantages, as it prevents people from looking at you and your preps with envy. Second, you can reach out to your neighbors and help them out by teaching them what you know, giving them tips on where to get certain items and gear and provide them with small handouts in case of desperate need.
Encourage your neighbors to start prepping before SHTF
Before a disaster even begins, you should start encouraging not just your family, bur neighbors and friends to start prepping.
Talk to them about the natural disasters that can occur in the community. Ask them how they are prepared for such an event. If they aren't, provide them with tips without sounding too pushy. Don't talk to them in terms of survivalism and extreme prepping. Focus on the practical and on their experiences with dealing with emergencies.
If they agree with you and decide from there on out that they will be better prepared for emergency situations, you now have a neighbor who will be a bit more ready for when SHTF.
From here you can push your neighbor more and more into joining the prepper community by encouraging self-sufficiency, asking them to join seminars and workshops related to survival and giving them prepping-related gifts, such as books, tools and gear they might need.
A prepared community has the best chance of survival
Reaching out to your neighbors is important. No matter how prepared you think you are, you will not be able to get very far with your preps without a community that you can look to for help. Dealing with hunger, inclement weather or looters is difficult. But, if you're a part of a larger community, these difficulties are significantly lessened.
When SHTF and you believe that you are the prepper with the most experience in your community, you need to take charge of the situation. Your community of novice preppers and non-preppers needs leadership now more than ever. (Related: No man is an island: The benefits of helping your community learn how to prep before SHTF.)