Of course you can.

It’s not a question of whether or not you can do it; of course you can.

It’s more likely a question of whether or now you are willing to do it.

Sometimes, we think we’re willing, but we’re really not.

And so we quit, fail, or give up.

If you don’t truly have a deep, burning desire for something (but you keep telling yourself that you do) then, it doesn’t work.