It may not always be wise to start working despite not feeling it. One could burn out that way. Scott H. Young write an article about this recently. https://www.scotthyoung.com/blog/2020/01/13/too-tired/ I have also experienced this. When I got my first job I actually tried to work all the time, besides the occasional breaks, ignoring feelings of tiredness. This got to the point where I was feeling tired pretty much all the time I was awake. Then I concluded I should give into my cravings for purposeless web surfing sometimes.