Socrates talked a big game in the Republic: we don't need money, family or friends to be happy; all that requires is that we pursue truth and wisdom. I can sort of see how this can make sense for highly intelligent people: for example Kant, Wittgenstein, Ergos... But is this possible for normal people with average intelligence? Can one truly live a lonely and impoverished life without becoming desperate at some point?
We don't know how far the 'Socrates' of the Republic, or of other Platonic dialogues represents the historical Socrates. Only saying.
As to the substance of your question, no-one leads a lonely and impoverished life in the Republic. There are three social classes (Rep. IV. passim): (1) the commercial and labouring class, who enjoy all the normal amenities of life. They can acquire money, marry, party, play sport and all other such things. They are excluded from political participation since they lack the requisite knowledge of the Forms, which are (roughly) the ultimate realities and values knowledge of which is essential to the correct conduct of politics.
Next we need to take account of (2) the auxiliaries (Rep. III.414B), who provide the military defence of the city (polis) and carry out the orders of (3) the Guardians who govern on the basis of insight vouchsafed by their knowledge of the Forms (Rep. VI passim).
The auxiliaries plainly cannot follow lives of self-indulgence; they need to observe the conditions necessary to fulfil their military role. But marriage is open to them as are the usual pleasures and enjoyments.
The Guardians are not 'lonely', since they form a cohesive, interacting group in the city as its governing elite. Nor are they 'impoverished' since the city makes full provision for their maintenance; all that is denied to them is, broadly speaking, personal property and marriage. They are not denied sex, indeed they are expected and required to have it in order to maintain the Guardian class over time. (Not all the Guardians' children will make the grade; 'inferior' offspring will be relegated to one of the two other classes just as some children of the other classes will be Guardian material and educated accordingly.) Guardian sex is, if I may put it so, collective; there are no permanent familial unions, there is only the necessary and presumably enjoyable activity of sexual intercourse after which each Guardian is assigned in due time her or his next sexual partner. The Guardians' children are brought up communally, none knowing who his or her parents are - any more than the parents know who their children are. All this is in the interests of Guardians' not having emotional attachments which deflect them from their pure devotion to public duty.
Who has sex with whom is strictly regulated during the Guardians' reproductive years (Rep. V.459D-E) but the controls are removed when the Guardians, female or male, have passed the age for producing children ((Rep. V.461B-C).
Life is demanding for the Guardians insofar as many of the normal forms of happiness are closed to them. Socrates realises that point; his main reply is that the Guardians have received a long and elaborate education at the end of which they have apprehended the ultimate nature of goodness and reality. This is an immense privilege and is itself so satisfying and transformative of their lives, raising them to such a plateau of enlightenment, that acceptance of the conditions imposed on them in governing the city is a moral obligation they owe in return to the city which has made provision for this education and its resulting enlightenment (Rep. VII.519C-520E).
Endnote on the average, normal person
Justice (dikaiosune), Plato tells us, is the health of the soul (Rep. IV.444C--445B). In regard to the social classes of the city (Rep.IV. 432B-434E) it obtains when each class performs its function, does its proper job (ergon). In the case of the Guardians, this means ruling. For the auxiliaries it consists in protecting the city and carrying out the orders of the Guardians. For average, normal people it means engaging in the ordinary business of life, in commerce or labour, not intruding in politics, and thus performing their proper function. As just, they enjoy the health of the soul : and to have a healthy soul is to be eudaimon - in a state of flourishing, well-being or happiness. So at least Plato holds.
We all know that there is none who didn't cry at least in childhood. I mean, if we consider this statement (the main issue) for one's complete life time, this is rather impossible.
Even though you abstain from money, the person who brings you up may be making use of money or something that does the purpose of money. But we can say like this-- "Money, family or friends cannot assure one happiness."
Pursuing of truth and wisdom is not an easy task. We can find this verse in Kthopanishad: KSHURASYA DHARA NISHITHAA DURATHYAYAA DURGAM PATHASTHATH KAVAYO VADHANTHI… - That is, THE DHARMIC PATHWAY IS LIKE WALKING ON THE SHARP EDGE OF A RAZOR. This implies, a person, when he is on the path of Truth, will not be happy always. But when he finds happiness within himself he can be happy even without all these three. You will get evidence from some Sanyasins who live in solitude.
You might have heard of/seen some spiritual devotees who see God everywhere. They may have average intelligence, but may have no money, family or friends. Even if they have no friends, they may be friends of all. The food given by others may be sustaining their life. Such devotees also may feel happiness; but it wouldn't be Socrates' happiness (Socrates' happiness is related to truth and wisdom).
Why many people propose this path (mentioned in the above para) for those who are not so intelligent? This link might supplement some ideas regarding this (Don't forget to imagine the three factors money, family and friends): http://www.yogabasics.com/learn/bhakti-yoga-the-yoga-of-devotion/
Happiness. It seems to me that among those accessing to the status of happiness are those who share at least one of the following features: a) Ignorance about the outside world. Just a person ignorant about misery around the world can achieve a state of happiness. Of course the Greek philosophers since they did not consider slaves as equals would be ignorant about the misery around them, for example. b) Ignorance about inside of the brain. A person can be aware of the misery around the world but might be totally [negatively] untouched by it, actually, he/she can inflict misery to those around him/her. In conclusion, it seems it does not make sense to set as an objective of life the pursue of happiness even for 1 standard deviation of the so called average person. Happy persons are so many because they are ignorant. It seems to me that we have to pursue OTHER objectives in life. Check the example of this Russian Princess living in London presented in the picture.