It doesn't help that we live in an age of instantaneous 'everything'.
Disappointment sucks, but it doesn't cease as one gets older.
Without expectation, there is no disappointment. There is no enthusiasm either, but there is no disappointment.
Disappointment = frustration. Frustration equates to venting so you aren't ate up with it. The best way to vent? Plug your guitar into your Kemper and jam out for 20 minutes. You'll feel better.