No it's not that rare.
Don't kick yourself - you wouldn't have gotten that block if you were solo mining since the work your miner would be doing would be different than that issued to the pool. You can think about all the what-ifs all you want, but then life would suck...
Statistically, are the odds of finding a block different when mining with a pool?
I understand going solo that months could pass with nothing, or maybe nothing his ever, but to even hit 1 block in a year has so much upside potential.