During the last series he did go through a lot. Losing Clara , going back to Galifrey they didn't exactly throw a party for him did they.

Plus at Christmas he got to spend a little time with River only to have to finally send her to burn in the library saving his 10th incarnation aka "Sand Shoes".

Wouldn't be surprised if he has some stuff bottled up. Being a man and a time lord it wouldn't be unusual for him to repress his feelings.

Girl who Died and Woman who lived explored the pain of immortality. Knowing anyone you get close to will age and die leaving you behind.

Zygon Invasion and Incursion were about his left over guilt from Galifrey and the time war. Protectign teh universe is not a easy job.

Hope he does get to have some fun with his new companion(s) when he meets them.

Well he doesn't really remember Clara and isn't really that affected by it as shown in the christmas special. And well he already seen River die, it could honestly be a relief that he finally took her to the Singing Towers as he doesn't need to think is this going to be the last time i see her.

I would expect him to be a bit mellow, but i think he would get excited and more upbeat if something interesting happens which it will.

i think he will just be enjoying himself going around in the TARDIS getting involved before the story of ep 1 leads him to the companion of that series

Yes, I agree with you. Whilst I personally think Clara's exit was a complete and utter mess, it does however erase a lot of the Doctor's internal doom and gloom.

So once we get beyond this particular incarnation's naturally un-jolly persona I think a new, unsoiled and upbeat companion and some fun adventures should quickly get him smiling.

I'm not expecting another grey, depressing season of episodes. Moffat's proven he can shake things up when necessary. I think he and the team at Who Towers know the show isn't going to win back any of those 1.5m lost viewers if they churn out more of the same.

He still remembers something of Clara, or that least the gap in his life, as the indication in THORS was that he hadn't laughed for a long time...

The one thing I didn't like about S9 was that 12 and Clara had fun adventures, but always unseen. We saw a lot of his angst at the prospect of losing her, hopefully he won't have this concern with the new Companion, and they'll have a good time (in between the not so good times!)

It sounds like he at least is confronting the need to let go, something he has admitted is one of his weaknesses. If he remembers most of the events of Hell Bent, if not the specifics of Clara, then he remembers that his inability to say goodbye led to risking the universe. It seems like this feeds into his interaction with River in this episode, where he decides to go along with the message the universe is sending him by ending up at Darillium.

So, yeah, I think he's had a bit of closure - his attachment to Clara, his relationship with River, his search for Gallifrey. He needs a new goal, and perhaps he might be feeling a little itchy and reckless.

I hope he purges all trace of Clara from his memory all she did is brought nothing but depression, I hope the Doctor is his fun self again like in THORT but less OTT but its ok if hes emotional now and again. I hope the new companion brings sunshine and warmth back.

I think we'll be teased with an abundance of potential new companions for the first few episodes.

The Doctor will be reluctant to take on someone after recent events.

There could be a few stories at the start where the Doctor travels alone, but the people he meets in each story could be made to seem like companion candidates to tease us. That could be fun.

OR

The Doctor goes completely the opposite way and travels with several different companions each week for a few stories, again to tease us, before eventually settling for (or forced to take) just one. That could be fun too.

Maybe he'll be forced to take someone initially when their home planet is destroyed.

But then again, given we are in these spoiler-filled times, could the real new companion be kept secret that far into broadcast?

OTOH, Oswin was given a "surprise" early introduction.

The Apprentice Doctor Who style

"Zak, you made a complete mess of getting everyone out of that lunar base, after I warned you about how you approached the Dalek last week. For that reason, you're fired!"

Probably just get another companion as always.

Horny. He'll seek out Capt. Jack and give him a Christmas present

A mixture of trapped wind, and achey hemorrhoids..