This might be a problematic question, but how do you know there are 5 skills specifically and how do they relate to the 90 day deadline?<p>I hate to sound like a programmer here, but having a project really helps out. If you can throw yourself in the deep end, then you learn by necessity, and each problem that comes up as you're going will hopefully tell you which part to focus on next, because that's your immediate issue. You'll also learn the parts you need, because the parts you need are the ones that come up with most frequency in your real world problem.<p>If its an artificial constraint or situation (and 5 skills in 90 days all decoupled from one another sounds like one, by which i mean a test or an interview), then perhaps its time to think about some strategy. If you can pick up the skills in several days each, they can't be that hard. If you know you're not going to be able to do it, perhaps its time to prioritize. Weight them relative to importance and focus on them each in proportion. Sometimes when you've got 5 tasks, you can get by passing on 3 or 4 and accepting absolute failure on the last one by skimming or ignoring it completely. This depends on your situation.<p>Personally, I find i can't learn anything unless I focus on a topic for a long period of time, then coming back and repeating it in shorter increments. Sort of informally imitating spaced repetition: See <a href="https://en.wikipedia.org/wiki/Spaced_repetition" rel="nofollow">https://en.wikipedia.org/wiki/Spaced_repetition</a><p>Personally though, it sounds like you're screwed. 5 topics with no cognitive overlap is a nightmare. Your task is likely going to be to come up with a strategy to make you proportionally less screwed rather than succeed at all 5.<p>But you are screwed :P