This advice needs to be interpreted the right way: don't butt your head against walls. Usually it makes sense to pick a task and finish it before going home.

This advice needs to be interpreted the right way: don't butt your head against walls. Usually it makes sense to pick a task and finish it before going home. If you stop just because its 5pm, you waste time re-orienting yourself the next day. Worse, you can get into the clock-watching habit. BUT, if at 4.55 pm, you realise there was some nasty wrinkle in the task and you need to rethink it or go back and do a big prepartory refactor, then you should go home and look at it with fresh eyes in the morning.