I won't lie, I'm feeling a little sorry for myself. There's no reason to be feeling down at all, it's a wonderful new chapter to the trip. The Trans Mongolian leg of the journey has begun and within 24 hours I'll be in Ulaanbataar.
It's just that when you're not in the mood, you're not in the mood.
The entire Russian female beach volleyball team could get on the train right now on their way to specialist training facilities in Mongolia, meaning I had to share my cabin with the three who are always chosen for the calendars and underwear adverts, I might still be feeling a little glum. OK, no I wouldn't, but you get the idea.
When you're full of zest the little problems seem like quirky charms.
Like when you smile politely and ask for a coffee, and are met with a look of utter disdain and a sour reluctance to serve you, it can seem funny when you're on top of the world.
Or when you're woken from a nap you desperately need by your cabin mate from Kazakhstan sitting on your bed, cracking open a bottle of vodka and getting two of his mates round to your place for a boozy lunch. When you're feeling on top of things you instantly bounce back and revel in the fantastic scene you're now a part of.
Or when you step aside to let the nineteenth person pass in the corridor on your way to the restaurant and they don't even give you a grunt of a thanks; normally it's water off a duck's back.
But as I sit here now looking a little forlornly out at the Siberian countryside that goes on and on and on and on outside the window of the restaurant car, past shanty little places where packs of dogs sit sniffing the air and human life seems to limp on in pain, having excused myself from the liquid lunch in my compartment, and let 19 people go past me without thanks, and been ignored then scowled at when, cap in hand, I tried to order a coffee; yes I'm feeling a little blue.
No doubt not helped by the fact that I didn't sleep at all last night. Sadly I only had a few hours in Irktusk, a massive error when I realise I've missed out on a chance to go to Lake Baikal, which by all accounts is breathtaking. Which is not surprising: it's the world's largest body of freshwater.
I still can't quite get my head around the fact that it holds 20% of all the world's fresh water, and if all of the water everywhere else on the planet suddenly evaporated in an instant, the whole world could drink happily from it for 40 years.
Maybe I didn't get to dip my toe in the world's biggest lake, but the train goes past one corner of it, and it is a majestic sight. If you dozed off and woke up to see Baikal, you'd think the train had somehow gone hideously off course and reached the Pacific Ocean. I'm definitely coming back to Baikal.
I chose to not risk oversleeping in Irkutsk by staying up and drinking beer in Harat's Pub near the hostel with a chatty boxing trainer who shared his chicken wings with me and talked sports politics. Apparently this was the reason why one of his female boxers wasn't picked to join the Russian Olympic team in London.
It was probably the right thing to do, well maybe not the beer, but I made the 04:52 train with plenty of time. But it was a cruel irony that I didn't even get into my bed at the Irkutsk City Lodge, which is a stylish little spot with sleek modern décor and very clean everything. After 55 hours on the Trans Siberian it's a wonderful little bubble. And that bed looked like it would have been good
But instead of sleeping the deep sleep of the nackered traveller, here I am in the restaurant car, hiding from the vodka session taking place in my cabin.
Not that I've got anything against them at all, they're very friendly and full of the same vim and generosity as most people I've met on the trains. But I don't have the energy this time.
Somehow it's not quite the same as when I shared solyanka with Svetlana and her daughter on the train from Moscow.
Or ate roast chicken and mashed potato with the lovely young family on the way to Irkutsk and played chess with their son.
Or stood at the window of the same train with Ayda from France and shared a set of earphones listening to the Verve as the sun rose behind us.
Not that I wouldn't be here for all the vodka on the Trans Siberian. It's just the way it goes when you're thousands of miles from home, on your own, sometimes it gets on top of you rather than you being on top of it.
So I carry on thinking about how blue I am but know that it's going to be ok. And as I sit here listening to music deliberately chosen to enhance my gloom, some noise distracts me.
I take out my earphones and realise that the whole restaurant car has burst into music. A Malaysian tour group are trying their best to sing a traditional Russian song, led by two patient guides and a few passengers who have joined in.
It's one of those moments that even in my morose state I can't help laughing at. Even the lady serving in the restaurant cracks a smile.
And then I look out the window feeling that little bit more cheery. All of a sudden the view looks that bit more intriguing.
The miles and miles and miles of trees have mainly receded and on either side of us huge flat plains with short green shrubs stretch out until the earth shoots up into hills and small mountains far away.
The Urals are well behind us, and soon Siberia, and Russia will be as well. We are very much in Asia now, and the whole atmosphere is very different, even if the service inside the train isn't.
Follow Benedict Cooper on Twitter: www.twitter.com/Ben_JS_Cooper