system
Given the following post, respond as if you're commenting on Reddit:
human
[Doctor Who] Why didn't The Doctor reveal who he was on Midnight?

You would have thought that it would make his job a lot easier if he didn't try to avoid questions so much. 

Why didn't he just say that he was a 905 year-old Time Lord from planet Gallifrey and that he travels through time and space with a human friend who is currently back at the leisure palace getting a lovely suntan? When asked about his name, he can just say that Time Lords don't have names, they have titles. When asked about why he knows what to do, he can say that in 905 years of his life, he learned how to be an electrician. He doesn't have to say "Because I'm clever!".

These people in the bus have seen aliens before, so explaining that he's an alien shouldn't be as much of a shock to them as it is to people like Donna. 

I think if he had just explained himself instead of pretending to be human, that issue wouldn't gotten has bad as it did. 

So, why didn't he drop the façade like he did on the Titanic?
gpt
Once the entity had entered the bus, it was more of a risk to reveal that he wasn't just an ordinary person. If the entity had discovered that he was super-intelligent, nearly immortal and had access to time travel then it would have made him a much more interesting target. While the Doctor has no idea what it is it's much more sensible not to reveal what he is. For all he knows, it's an entity like the Family of Blood that's been searching for a Time Lord body to live in.

Before all that happened, he just wanted to be an ordinary holidaymaker having fun, he didn't want to stand out in any way. There's also a high chance that Time Lords are a legend to humans at this time period and they wouldn't believe him even if he did tell them.