Posted: 29/04/2014 at 19:01
Hi Fluffy, they really need to be left to die back naturally as the leaves are building up the bulb for next year's flowers. Once the leaves die back you can lift them. Many folk (me included) leave them in the ground, but it's best to plant them 6 to 8 inches deep if you do that. Some folk treat them as annuals and discard them after flowering, especially if planted in pots. I think that's what you have effectively done, albeit by accident!
There is no one answer to how long they live - I have some that have been in the ground for 30 years and come back every year (plain red and plain yellow ones), but most of the fancy ones I buy rarely do well the following year.