Settling implies getting less than what you want. That's not the same as having reasonable expectations.
All healthy relationships involve some compromise. Yes, 'perfect' partner doesn't exist. Live with someone long enough and they will drive you batshit crazy on some issue(s). The glue that holds you together during these times are the good things about your relationship. On balance, good times >> bad in a healthy relationship. Mutual respect, support, a sense of humour and genuine fondness for each other. Find someone you can feel this for. Cultivate those things together and you'll weather the difficult times.
Second thoughts can generally be amended with judicious action; injudicious actions can seldom be recovered with second thoughts.
--Cyteen by C.J.Cherryh