Worst relationship mistake that you could wish you could take back?

the one thing i regret the most in my relationship, cause i've only had one so far, is faking a break up. I used to break up with my boyfriend all the time because i love the feeling when he begs me to stay. So even though there are times that we didn't have problems, I'd break up with him for no reason. I learned my lesson when I broke up with him again he agreed and said " You're right, i think we should break up." After that i spent a whole year being a martyr just to prove to him that i do love him.

i think the thing i want to take back is the chance i didn't give to an ex. i was immature and all i wanted was to have my way so i got rid of him without even thinking of things. i usually wonder what could have happened if i gave him a chance he once asked.

"Worst Relationship Mistake that you could wish you could take back?" Entering them in the first place. Plenty of wasted time and effort on some pretenders and harpies.