Stop waiting. Stop waiting for tomorrow, or the weekend, or the summer. Stop waiting to excel at a later date or improve at a more convenient time. Stop waiting for him to text you back or her to approach you in class. Stop waiting for this month to end, your birthday to celebrate, and time to fly. Stop waiting and go now.
Why is time of day, day of month, or some other thing you have no control over prohibiting you from living your life to the absolute fullest? I get it, we have comfort zones and we love to run around and "live" life inside of them, but have you truly lived if you have not pushed your limits? Plain and simple answer; no. You're tired of hearing, "Life is too short" but that's probably one of the most honest phrases we should all accept. Life is too short and uncertain to not satisfy our needs, desires, and wants while we still have the time to do so.
Stop waiting and go now. Stop waiting for something to happen to you and go make something happen. Measure life by the challenges you construct and conquer, not by the challenges that you meet. Stop waiting. Go.