@tangovictor.
You are half right and half wrong Sir in regard retiring to the USA.
yes on a normal visa waiver permit (ESTA) it is a maximum of 90 days per visit.
But you can apply for a residents visa which is renewable annually, you don't have to be a multimillionaire to be accepted, but you do need to prove you have sufficient funds to live unassisted in the US without the need to seek employment. And decent medical cover is a must, because if you need any serious medical work and can't pay they will take your house, car and shirt off your back....
We have a home in Florida, and we visit 4 times a year for stays of 5/6 weeks each trip, although not fully retired yet, it is our intention that once I have called it a day we will retire there. I have already met with an immigration lawyer to work out the details to make sure when the time comes we comply with the resident visa requirements.