You`ll never really know,sometimes when everything is finally put together you might have a moment of clarity and realise the simplicity of it all, but it doesn`t last and you have to start again next time,guessing,ordering the wrong bits,over-ordering etc.
Eventually though you`ll have a plumbing war chest and be able to adapt a 6mm hose tail to Hozelock with only 9 intermediate joints,11 jubilee clips,2 rolls of ptfe and a combined weight of only 10kg.