lily, I haven't rejected what I was taught about being good. I've rejected religion. Two completely different things, being good (or trying to be) and being religious. I still have time to reflect on my doings, good and bad, without Lent. Therefore, to me, Lent is pointless.
This is how I feel too. I always went to church, was in the choir and several other groups within our local Parish. Various things happened in my life and I began to question things. Eventually ,I came to my own conclusions and do not now believe or attend church. I don't feel I have lost anything and certainly I still try to be 'good' although like many of us I often fail. I'd say that these days I work on the principle of Do as you would be done by.