Give it your best shot!
“That’s a nice attitude, but giving your best doesn’t always work.”
That’s a nice observation, but it’s irrelevant.
Giving your best isn’t valuable because it always works. It’s valuable because it’s better than living a half-ass life and because it beats giving your worst on any day of the week.
Once you truly develop a deep respect for who you are, what you want, and how much better your odds are when you actually give a damn about your life, you’ll see the possibility of failure for what it really is: a poor and absolutely unacceptable excuse for not doing the best you can do with what you have.
If you give your best, you just might lose. That doesn’t mean you should deliberately decide to be a loser by giving up on yourself ahead of time. You don’t need guarantees. You need self-respect.
Have some standards for goodness’ sake. You deserve it.