of / in

[Snow Lau]

Hello!!
The following sentence :
1) He told me that it was the happiest occasion in his life. or
2)He told that it was the most happiest occasion of his life.

Which sentence is correct? I should use in his life or of his life? Why?

Thank you!!

[Casiopea]

Hello!!
The following sentence :
1) He told me that it was the happiest occasion in his life. or
2)He told that it was the most happiest occasion of his life.

Which sentence is correct? I should use in his life or of his life? Why?

Thank you!!

Either 'in' or 'on'. 1) means, inside his lifetime, whereas 2) means, belonging to his life. Both 1) and 2) are near synonyms.