Yeah. The things you can and can't say for uncountable nouns are a little inconsistent. You can't say "one intelligence", but you can double intelligence, add up intelligence and even calculate intelligence. Same for other uncountables: Learning a language takes double the effort needed to learn an instrument. If you add up all the energy you spend on it, it's a large amount. Sometimes it's hard to calculate the total time you need. As ever, the best example of an uncountable is rice. You can't ask for one rice (what is it? one bowl? one cup? one grain?) but you can certainly eat double the rice I do. If you want ;)