This is an interesting (and obviously very personal) poem. I really like the parenthesis here, the "Life has changed since you were a mere, drunken teenage boy." I think it does the best at expressing how you're feeling without actually telling us. Most of the poem seems to be you just saying how you feel, but I think you'd benefit more by experimenting with that voice you use in the parenthesis because it was a very interesting line. Keep writing and good luck!