Although getting a grant is a top 10 professional good feeling, the lead-up is really a drag.
First of all, grants are really competitive. There are more research projects than magic pots of money, and so you are always a loser more often than you are a winner. You also compete against your closest colleagues and mentors. Even the most collegial group of scholars can get bent out of shape when one person appears to be getting a bigger slice of the grant pie. It's also exhausting to put so much effort into applications that you know do not have a good chance of getting funded.
This competition makes writing grant proposals tedious. It's always important to tailor a proposal to the interests of the granting institution, but there's also a lot of pressure to make your application stand out in the crowd. There's a fine balance that you have to strike between familiar and innovative--you want to propose a project that a funding committee will understand, but that isn't something they have seen 100 times before. It has to appear fresh, but feasible. That's a tall order!
It's hard to stay calm through a process that feels like an exercise in futility, but the good news is that most every scholar hits the jackpot now and then.