I just have work to do; I just do it.

dont wait for next minute, next hour, next day, next week, next year, just do it if you want to do it...

There's doubt in trying.
Just do it or stop thinking.

Just do it... that's all... no matter what, when and where... but just do it.

I'm this overachiever type, I'll just work and work and I'll just do it over and over and over again.

Throw caution to the wind and just do it.