We've both learned a lot about each other over these past five years. Some things I have learned NOT to do:
1) Don't antagonize him right before bed or HE WILL sing all 5 million verses of some old hymn he knows
2) Don't buy him an outdoor thermometer for Christmas. Stick to presents with cords.
3) Don't try to stop him from mowing the lawn - it's important to him.
4) Don't cock the pictures on the wall or the coffee table from being at a direct parallel to the sofa
5) Don't underestimate his creativity, talents, or abilities...I am continuously amazed at how amazing he is at whatever he attempts. Well, except for plumbing...that's ok =)