Can I return to Thailand on a 30-day visa exemption after traveling to Cambodia and Vietnam?

The original question pertains to the possibility of returning to Thailand after a trip to Cambodia and Vietnam while currently holding a 30-day visa exemption. Answers confirm that upon exiting Thailand, the current visa exemption becomes void, but re-entering Thailand will grant a new visa exemption, typically for 30 or 45 days depending on the date of re-entry. There's no specified limit on the number of times one can utilize this exemption, but travelers should confirm current immigration policies.