One of my beliefs (influenced largely by John Fowles) is that people are in a constant state of change. Our bodies and our minds are altered throughout our lives, so that it only makes sense to think of life as shifts and continuums and breaks and conversions and evolutions. We develop. We grow. We learn. And our ideas change.
It strikes me, however, that not many people believe this. A lot of people are under the impression that people don't change terribly much. And a lot of people don't give room to people to change, either subtly or drastically. That somebody thinks something different at, say, 30 than one did at 20, should be taken for granted. But we don't quite do that.
We often hold people to what they were at a time when they weren't what they are.
In some cases, that's necessary. In others, it makes little sense to me. We're in a constant state of flux. We're always changing. And while I'm not saying that a person shouldn't be accountable for what he/she did at a different time in his/her life, it should be easily understood that a person is different at different phases.
A change in ideas, a new understanding of the self and the world, is only natural.