It's a sarcastic response.
Taken literally the sentence would mean the speaker isn't already familiar with the situation and wants more information. However it is rarely (these days never) meant literally, and is used sarcastically to mean the opposite. I.e. That the speaker is already familiar with the situation. Its meaning is similar to the expression, "You don't say?", where the speaker is acting like they don't already know, when in fact they do.
The difference between these two expressions however is that, "Tell me about it", has taken on a sympathetic tone over the years, indicating shared misery, whereas, "You don't say?", is an insult where you don't actually care what the person has to say.
There's little in the words themselves to indicate that difference. That difference is simply the connotations those expressions have taken on over time. Tone of voice is pretty critical here, because the difference between a sympathetic statement and an insulting one is simply a different inflection while saying the exact same words.
‘Juices’ is a kind of slangy term that means ‘a person’s vitality or creative faculties’. The creative faculties are of course what is referenced in the expression mentioned in the question linked to by jwpat7 in the comment above; in this case, it’s the other meaning we’re looking for.
Since a person’s vitality is seen here as a kind of ‘juice’ (originally most likely referring on some level to bodily fluids: especially blood was, in Mediaeval times, often considered to be a source of energy, health, and vitality in humans), it makes sense that it should be set ‘flowing’, since that’s what liquids do.
This meaning is extended from the meaning the OED has as sense 2:
The fluid part or moisture of an animal body or substance; now usually in pl. the various liquid constituents of the body, the bodily ‘humours’
Obviously, if you think of it as being ultimately just a kind of euphemism for blood (and sweat and bile and all the other humours), getting it to flow, and flow faster especially, would be a sign of physical exertion or excitement: when we run, our blood actually flows faster, and our pulse increases.
The phrase is often also used in a sexual manner, where the reference is to the various kinds of sex-related bodily fluids that are released when people become aroused. Whether the sexual meaning came first or the exertion meaning came first (or whether they are really to be separated at all), I do not know; I cannot find any quotes for that. But it is clear that they are both in use.
In the quote from your NYT article, the meaning is definitely that of physical exertion–based excitement. He is comparing the ‘rush’ he gets from driving to a kind of race where he’s not going to let anyone pass him and be faster than him.
Best Answer
The origins of the expression “cut your losses” date to the early days of the London Stock Exchange, founded 1801. The original form was “cut short your losses” and was popularly attributed to the economist David Ricardo (1772–1823), though this maxim never appeared in any of his published works:
A brief biographical sketch of Ricardo prefacing this rule became part of financial lore and is still told today:
The second and third rule have conflated to one, and both phrasal verbs have lost their particles. The shortening to a single aphorism occurred already in the 19th century:
Divorced from any mention of Ricardo, the maxim could vary:
An NGram shows that around 1900, cut your losses short began to be more frequent, most likely because of the more pleasing rhythm. At the same time, more and more speakers were, as the 1852 Merchant’s Magazine article suggests, applying the maxim “with advantage to innumerable transactions other than those connected with the Stock Exchange.” The saying has entered general use divorced from any connection to stock trading and can describe getting out of any bad situation before it gets even worse.