Switching Partners

So me &my SO broke up about 3 weeks ago. I've taken up knitting &it's been helping me get over him (which is weird). He was my first on everything even sex & I don't regret it at all because I really cared for him &he cared for me. It hasn't even crossed my mind to have sex with someone else but I was just wondering on how you girl &guys got over your first &knew when it was ready to have sex with someone else?