Blog gadfly and MFJ connoisseur CPP has a post titled "Grantsmanship is a Stochastic Process." If you are, or will be, involved in grants in any way, even peripherally, you should read it.
He's right. It really sucks living from grant to grant, knowing that you're just one rejection away from closing down your lab. I was once in that position. I got lucky and dug myself out. Don't do what I did* - too many don't get lucky and end up with nothing.
* Sometimes I think my role in life is to be a warning to others...