i am not sure what your current country of citizenship is so I will speak from my perspective and experience (I'm a US citizen).
Short answer: YES, you can live in Thailand.
Longer: you cannot just show up and on day 1 start living there for the rest of your life. for US citizens we get to enter for 30 days as a tourist, which we can extend for another 30 days. now, that allows me to "live" there for 60 days before I would have to leave. you can also now get a 6 month Tourist Visa whereby you can stay in the Kingdom for 90 days before having to leave.
i personally have a 1 year multiple entry visa. this allows me to come and go throughout the year, provided I never stay for any longer than 90. I just need to leave for at least 1 day. no, they don't time me for 24 hours but i need to exit/enter. I have this type of visa this because I do business consulting. i work for and own US companies. i also own a mexican company.
there is the option for approx $15,000 USD (as the gentleman mentioned above) to get what is called an Elite Visa. This allows for a 5 year Visa and you simply report (via a website) to the Thai embassy where you are living, every 90 days.
Another option is buying a new condo. Many new developments provide a 5 year or even 10 year Visa if you buy a condo of a certain value (e.g. ~$50,000 USD) there are many advantages to this option BUT as with any real estate (or any investment for that matter) in a foreign, there are always risks. But i always look at it like, "the justification for private profit is private risk".
There are for sure a lot more options but honestly its all pretty simple. There are many places on the Internet with incorrect or complicated information.
Another recommendation I can offer is contact a law firm. There are MANY in Bangkok. From world-class firms like Baker-McKenzie to boutique firms that are much more nimble and specialize in Visas for foreigners.
If you have any specific questions, feel free to contact me. Happy to help.