This is not the right attitude to have when you're starting from square one. EVen if you learn something that isn't immediately useful its still valuable progra

This is not the right attitude to have when you're starting from square one. EVen if you learn something that isn't immediately useful its still valuable programming experience and since you're picking things that will be relevant to building apps it will most likely be relevant later on or in another project. You can't just skip the baby steps and expect to be able to cultivate a expert level understanding of the technical tradeoffs involved in designing a system. You're more likely to get stuck in an analysis paralysis if you aren't willing to take small suboptimal steps towards your end goal.