You're not crazy. I can't work out how to get around this myself. I come across it most often when tasting a dry hopped, green beer on bottling day. Big punchy hop taste straight out of the tank, then by the time its bottle conditioned the flavour and aroma have all but disappeared. Apparently the C02 released during fermentation (or on opening the bottle) "scrubs" some of the flavour molecules out of the beer.
Tried adding more hops but that gets expensive and the phenols in the hops negatively effect the clarity of the beer. Looks like I gotta invest in a keg system and force carbonate.
Then again I'm only on my 7th brew so maybe I'm missing something.
Edit: Bosher's right though dry hopping will help some, just make sure you drop the hops in the fermenter after your initial fermentation has calmed down. I usually do it on day 5 or in secondary if I'm doing one. Separately boiling some hops on flavour addition timescales (20min, 15min, 10min etc) and adding those to the fermenter after initial fermentation may help too but I haven't tried this.