I Can't Go Back to My Youth

I have been regretting it since I grew up. I regret that I didn't work hard, study, or persevere. But when life doesn't come back again, I really want to cherish it, but time is like the sand in your hands. The tighter you hold it, the faster it flows. If time could go back, would I still regret it? Time has really turned back, and the legendary system has appeared. Is this world real? Purpose: Cherish your time and work hard, time will carve you into what you should be