Apart from children, of all the things that give life meaning, I think directional motivation with proper amount of slack is best. Try to achieve something too hard, and in the long run you´ll feel spent. Get lazy, and you are filled with irritation and sometimes even certain amount of shame. As countless people have said, its all about balance. So ´go for it´, but go with a smile.
This dynamic flux of doing and not doing can be broken down within myriad of tempos. Within one single day, one should usually find intense and loose moments. Its the same when applied to a week, a whole season, one whole year and so forth. Its natural! Rest and work, growth and stillness, soberness and pure unlimited silliness should all take their turns.
There are great personal differences regarding what is natural at any given time of course, and in this way as individuals we all bring valuable variety to the whole. If everybody would act and feel the same, things would become stagnant and in the long run unhealthy. On the other hand, too much contradiction and contest, and our social experience and reality would weigh unnecessarily heavy on us.
I´m propably trying to say something lofty here, so my next post will be utter nonsense. Balance, remember?