The phrase is usually "get a life" rather than "get some life." The person who says this feels the person to whom it is said is wasting his or her time on something. Wikipedia has good examples:
http://en.wikipedia.org/wiki/Get_a_life_(idiom)
Implied in the taunt is to act normal (whatever that is!) or mainstream.
“To add more water to the beans” is a Latin America saying that means to share what we have with the extra people, to spread it around further. There are songs about this.
The English wording was just a word-for-word verbatim translation. The actual Latin American phrase would be one of these two, depending on just which one of the two dominant languages there was being spoken at the time:
- Spanish: poner/echar más agua a los frijoles
- Brazilian: botar mais água no feijão
It’s something of a catch-phrase there. See here, here, here, and here for a couple of examples in each of Spanish and Portuguese.
On this occasion, Papa Paco made his remark in Portuguese, saying sempre se pode colocar mais água no feijão — “one can always add more water to the feijão”. It’s a popular Brazilian saying. You can listen to the Pope saying this here. He has a bit of a Spanish accent, but it’s not bad. :)
A transcription of his speech reads:
Desde o primeiro instante em que toquei as terras brasileiras e também aqui junto de vocês, me sinto acolhido. E é importante saber acolher; é algo mais bonito que qualquer enfeite ou decoração. Isso é assim porque quando somos generosos acolhendo uma pessoa e partilhamos algo com ela – um pouco de comida, um lugar na nossa casa, o nosso tempo — não ficamos mais pobres, mas enriquecemos. Sei bem que quando alguém que precisa comer bate na sua porta, vocês sempre dão um jeito de compartilhar a comida: como diz o ditado, sempre se pode ‘colocar mais água no feijão’! E vocês fazem isto com amor, mostrando que a verdadeira riqueza não está nas coisas, mas no coração!
In other words, when we are generous and share a bit of food with someone, a place in our home, or our time, we are not left the poorer for it, but richer. He knows that the Brazilians will always find the means to share food with someone at your door who is hungry, because of the saying that one can always throw more water on the bean pot.
In English, we might simply say that “there’ll always be enough to go around”, or to “set another place at the table”.
Best Answer
Meaning (of "long drink of water") is ambiguous, just generally meaning "tall", as reflected in answers here, though specific use can have connotations of "tall and attractive (man/woman)" or "lanky, gangly" (tall and awkward).
The origin appears to be Scottish, dating to Scots lang drink (1887), as suggested by the 1924 quote from Mo Nickels (MetaFilter), quoted by Little Eva.
The Dictionary of the Scots Language cites (at drink and lang):
(I've put this at long drink of water at Wiktionary for reference.)