PACO is correct.....if you rely on electronic methods totally then you will eventually learn the error of that concept. There simply is no viable replacement for fully understanding the basics of navigation and map reading. With practise and many hours of tooling about regular routes/areas' then retained information from previous experiences will make the fundamental process quicker.
If you are doing the same route the same way continuously, well even then to set off without a line on the map and the rest of the basic data is not only foolhardy but damn stupid. IMO the minimum is that which is sufficient to allow you to transit the planned route safely without any electronic aid.
Best Wishes