Do I need to purchase a flight ticket out of Thailand while on a student visa after traveling abroad?

The original poster inquired about whether they needed to purchase an onward flight ticket upon re-entering Thailand with a valid student visa after traveling to the UK. Responses indicated that an onward ticket is typically not necessary, but they should be prepared for scrutiny and questioning at immigration, especially regarding their departure from Thailand while on a student visa. It's advised to have a letter from their school and any supportive documents to explain their absence. A fellow expat shared a personal experience of being questioned and suggested that switching to a marriage or dependent visa might involve less scrutiny.