I'm really sorry if there is already a thread on this topic, anyway...
Why "I" is always written with a capital letter?
My lecturer's explanation was: "I'm God's work so I deserve to be written with the capital letter". Is this right?
The reasons most often given for the capitalization of the personal pronoun are varied. Most of the theories have at least some fact or logic in their favor. Your lecturer's explanation is supported by neither.
Have a look at the link from post number 3 of this thread:
Well, not necessarily. One who believes in God can ignore the real reason, thinking that the God-reason is the right one!
Anyway, at first I accepted this explanation but now I think that the (eminently) practical reason is correct or, at least, the most plausible one.