All the "missed the train" laments over selling off Bitcoin holdings can be compensated for, by just buying or mining all the newer competitors (litecoin, feathercoin, dogecoin, etc). These crypto-currencies are receiving the same laughs now that BTC received circa 2011, but are built on the same foundation, namely built-in scarcity, as only a specific number of each will be generated by the software.
If you buy it now for almost nothing and just wait, the worst that will happen is almost nothing. If their value jumps by just 10x in 4 years (a mere fraction of Bitcoin's rise in value), you'll make 10x your money. Play the long game and win.