So some asked me when do you know when it's time to retire/call it quits? I would like to know how you all would answer this question.

Whether the choice was yours, your spouse's/family's, medical condition or you ran into one of the military's service length requirements, when did you know it was time to hang the uniform up for the last time?

Thousands of service members retire each year...your responses may impact their decisions.

Note:  Keeping your responses short will allow for more views/responses.