This is what I often refer to as "the curse of the competent." Future me will always have more complete information than current me with regards to what current me is doing at this time, and that will always cause me to evaluate past performance in a more critical light. Also, as you continue gaining knowledge in a particular field you become aware of how much more there is to learn. It's constantly resetting your opinion of "how much you know" which can lead to statements that from an external observer appear to be unrealistic.