If I had received a pound every time I've heard someone say "Oh, I speak X languages, I'm sure I could be a translator"... Funnily enough, it's usually followed by the question "How much do you actually earn?" This just shows the common misconception that speaking 2 or more languages is enough to be a translator, and an easy way to make money. Of course, it couldn't be further from the truth, and as a professional I find this statement quite insulting.
My usual reply to such statement involves something along the lines of "Well, could you write a novel in your native language?" "Or hold a conversation on nuclear physics?" The point I'm trying to make is that to be a good translator, first and foremost you need to have an excellent command of your native language. And that does not only imply being able to write without grammar and spelling mistakes (which, believe it or not, it's quite a challenge for some people), but also to use the appropriate terminology, tone, register, etc. As we say in the translation industry, the text has to be "fit for purpose". In addition, a thorough knowledge of the source language is also needed so that you can understand all the subtleties, hidden meanings, puns, etc. and convey them in the target language. This is by any means no easy feat; as any translator will tell you, translating puns, sayings, wordplay and similar expressions can be a nightmare, as most of them do not have direct equivalents in the target language, so you have to stretch your creativity to the limit.
In addition, as exemplified by my "nuclear physics" question, a translator needs to know inside out the field they work in, be it games localization, mechanical engineering or legal contracts. It's simply not possible to know absolutely everything about anything in the world, and that is why translators usually specialise in 2-3 fields. In order to get the terminology, style, tone, etc. absolutely right they need to understand the text to the level of a professional who works in that field. In fact, it's not uncommon for legal translators to have received legal training, or for games localizers to be avid games players, for instance. Usually, it's quite easy to tell when something has been translated by someone who is not familiar with that subject area, as they pick slightly different terminology or simply don't stick to the "conventions".
And last, but not least, it's also important to consider that most translators are self-employed. This means that, in addition to their linguistic knowledge and their command of their subject areas, they also need to have business skills. They have to be savvy enough to carry out their own marketing campaigns and get new clients (which presumably they will keep with their awesome translation work!), manage their websites, blogs and other media presence, manage their income, sort out their taxes and do accountancy work (unless they use an accountant), etc. And if you think this isn't enough, you can also add more administrative tasks such as providing quotes (which might or might not lead to projects), answering queries by e-mail or phone and project management (in the case they subcontract work or collaborate with other translators).
So, who still thinks that being a translator is easy? Don't get me wrong, translation is one of my passions and I very much enjoy it, but it's definitely not as simple as speaking 2 languages.