Thai men are not required to become monks during their lives, but they are strongly encouraged. You must vow to obey 227 rules of conduct, including poverty, chastity, etc. You can choose to remain a monk for as long as you want after the minimum stay. In the Buddhist scheme, becoming a monk not only gives merit to the man, but also to the man's whole family. Hence you see mothers urging their sons to become monks so that the whole family can benefit.
Buddhist temples are fabulously ornate.
Conduct inside a temple is often different from a Westerner's expectation. Particularly, we tend to equate a Buddhist temple with a Christian church. The significant difference is that the Christian church service is a corporate affair, where the people assembled participate as a group. In the Buddhist temple, though, the worshipers are very individualistic. Each person is carrying out an individual ritual strictly for himself or herself, so you can walk around, watch, engage in conversation, etc.