Imagine arriving at the Sacrament of Reconciliation just in time to see Jesus walk into the confessional.
After getting over the initial shock, you would probably assume He was going in to forgive your priest.
But imagine that instead, you watched as your Savior walked out of the confessional, and into a pew to start praying His Penance.
Imagine our perfect Lord going through Confession just like we would. It wouldn't make any sense, right? He who is sinless doesn't need to be forgiven!
I imagine that is how John the Baptist felt when Jesus asked to be Baptized. It probably made no sense to him because Jesus was already pure.
But sense or not, Christ still felt it was important to set an example for us.