Self-sacrifice and a lack of selfishness would change my mind on a huge number of political issues.
Martyrdom squads would quickly change my mind on unjust wars.
Abstinence (romantic 13th century style, think Dante and Beatrice, or I guess more appropriately, David and Jonathan from the Bible) marchers in gay pride parades would change my mind on gay marriage.
Bringing back the Students Today Are Not Ready For Sex abstinence sex-ed program would be a huge improvement over all the other programs I've seen, including other abstinence programs. Also, we need "virginity promise" rings for guys to be given by mothers.
Campaigning to bring back the Philadelphia Nun's Loophole would change my mind on the Tea Party protesters. Giving up getting high and not trying to be superman and stop commuter trains would change my mind on the Occupy Protesters.
Taking a cab home would certainly change my opinion of people who get drunk away from home. For that matter, people over the age of 80 really need to consider public transportation rather than continuing to drive as well.
Getting the picture? Denial of self is good for not just the individual, but good for society.