You don't need one person doing a 180. Two people doing a 50-70 in opposite directions is more than sufficient. Which happens more often than you'd think, and is no doubt a contributing factor to high divorce rates. No one ever sets out to find "the wrong person". I expect near 100% of people getting married think they've found a great fit. It's just that what constitutes "a great fit" changes a lot from, say, your late teens through your late thirties, and there's a lot of pressure on people to marry young so they can crack on with making babies and the propagation of the species. If someone gets married at 18 and then at 28 discovers they "married the wrong person" my reaction would be "well it was a 50/50 shot at best".emeraldrafael said:when I say the wrong person, I mean someone you can live with. I know people change, but if yourein a good relationship unless they pull a drastic 180 transformation (which if so then there's something else wrong or most likely could have been prevented with some small actions) then you should generally be able to cope and adjust as well. I like my dads philosophy of living with a person for at least 2 years before you even think about marriage. Gives you enough time ot see the person, see the family, see if theres anyhting at all you think could be early signs this wont work and generally is a strong indication of how the relationship will go.
There's then the question of whether or not people should "cope" with relationships that no longer fulfill them or make them happy for the purposes of a vow, which is why we have the concept of divorce in the first place. I don't think there's anything wrong with saying "We did our best, but this has run its course". The fact I can and have been able to say that has left me good friends with almost every ex I've ever had, one of whom is like a sister to me. Conversely, long and bitter divorces have turned previously loving couples I know into hateful foes. Naturally this is my anecdotal experience and as such isn't worth a hill of beans, but there you have it.