Means that if you don't do it, you will regret for the rest of your life! So DIADRI! Do it and don't regret it!
Me: ''I would so try that out, but got no time!''
Him: ''Promise you, you won't regreit it! If you don't make that bungee jump you would regreit it for life!''
Me: ''But got no time.. well.. DIADRI!! ''