It may amount to stating the obvious, but Mathematica is based on the fundamental ideal of starting everything early, not premature, just, early enough for there to be enough time for anything!
Some things take time to slowly register, assimilate, blend and cement. Mathematical concepts need time to learn. But, once you understand them, they are yours!
If you need to go shopping, and it is a 45-minute drive, it will be silly to tell someone on the phone, you would be there in 45 minutes. There will be time from the phone call to the time you actually leave home; add to that the time to wait for transport, what if there is more traffic today, not to forget the time needed to come out of the vehicle and walk up to the shop. So, unless you’ve told your friend on the phone you will be there in 90 minutes, there is a high chance you will be late. So, always and forever, let’s start early!