Me and you might not even get on.

[shootingstar]

(Nora's brother Joe speaking) 'I saw this great documentary about Greenland the other night. Made me remember when you were obsessed with the Artic and you cut out all those pictures of polar bears and stuff.'
'Yeah. Mrs Elm said best way to be an artic explorer was to be a glaciologist. So that's what I wanted to be.' . . .
'Just think, if you hadn't stuck with swimming, you'd be in Greenland right now.'
'Svalbard,' she said.
'Sorry?'
'It's a Norwegian archipelago. Way up in the Artic Ocean.'
'Okay, Norway then. You'd be there.'
'Maybe. Or maybe I'd just still be in Belford. Moping around. Unemployed. Struggling to pay the rent.'
'Don't be daft. You'd have always done something big.'
She smiled at her elder brother's innocence. 'In some lives me and you might not even get on.'
'Nonsense.'
'I hope so.'
Joe seemed a bit uncomfortable, and clearly wanted to change the topic.
(The Midnight Library by Matt Haig, episode Peppermint Tea)

What does "might not even get on" mean in this context?

 

[5jj]

get on​

British
1. phrasal verb B1
If you get on with someone, you like them and have a friendly relationship with them.
The host fears the guests won't get on.
What are your neighbours like? Do you get on with them?

https://www.collinsdictionary.com/dictionary/english/get-on

 

[shootingstar]

get on​

British
1. phrasal verb B1
If you get on with someone, you like them and have a friendly relationship with them.
The host fears the guests won't get on.
What are your neighbours like? Do you get on with them?

https://www.collinsdictionary.com/dictionary/english/get-on

However, there isn't any "with" in this sentence. Doesn't it have to be "In some lives me and you might not even get on with" then, or "In some lives you might not even get on with me" ?

OK, I see the first example "The host fears the guests won't get on" doesn't have the "with" as well. However, isn't that inconsequent? Doesn't it have to be "The host fears the guests won't get on with" ? What I mean, isn't the "with" mandatory regarding this meaning?

 

[emsr2d2]

However, there isn't any "with" in this sentence. Doesn't it have to Shouldn't it be "In some lives, me and you and I might not even get on with" then, or "In some lives, you might not even get on with me"?

Your first suggested sentence is ungrammatical. You'd need to either add "each other" after "with" or remove "with". The second suggestion is grammatical but it only refers to "you" getting on with "me". You've lost the idea that both people are involved.

OK, I see the first example "The host fears the guests won't get on no full stop here" doesn't have the "with" as well.

That's correct.

However, isn't that inconsequent?

I don't know what that means.

Doesn't it have to Shouldn't it be "The host fears the guests won't get on with"?

No. That's ungrammatical. It doesn't say who the guests might not get on with!

When all parties involved have already been mentioned, we can dispense with the "with" part.

My brother and I don't get on. (The two people involved - my brother and I - have been mentioned so the "with each other" is implied.)

The guests don't get on. (All the people involved - the guests - have been mentioned so we don't need "with each other".)

Of course, there could be more than one person at the start of the statement but there's a third party.
My brother and I don't get on = My brother and I don't have a good relationship with each other.
My brother and I don't get on with our sister = My brother doesn't have a good relationship with our sister, and I don't have a good relationship with our sister, but we don't know if my brother and I have a good relationship with each other.

 

[Skrej]

get on​

British
1. phrasal verb B1
If you get on with someone, you like them and have a friendly relationship with them.
The host fears the guests won't get on.
What are your neighbours like? Do you get on with them?

Just a note to learners that this is a distinctly BrE phrasal verb in this context.. AmE would use 'get along (with)'.

While 'get on' does exist in AmE, it has the sole meaning of 'board/enter' (typically transportation other than automobiles).