Leaving every 6 months

Guys i thought we had to leave every 6 months to avoid being a tax resident, but after researching i’ve seen that if you’re in thailand for more than 180 days within a year, regardless of if you leave every 6 months, then you are a tax resident. is this true? + if it is does anyone know the reason as to why we have to leave every 6 months and reenter? i’m just curious

thanksss

If I retire to Thailand and get my pensions paid into my Thai bank account,would this income be taxed by the Thai government ?