that's because people say they have a visa, when they are already in Thailand. Whereas the visa has actually been used to enter and is finished. . They no longer have a visa but a permitted stay. It's all about understanding terminology.
I'm guessing you've never travelled and had travel insurance before. People generally take it out soon as they book their flight so everything is covered from day one. *Edit. Yes a 7 month policy at home might take a bit of a search.
Get in your home country or country where you live, before arriving. You'll have the visa issued by the embassy and can show to immigration and use it to get your permission to stay.