My ameryliss flowered 2 years ago and I left it in pot on kitchen window in corner behind curtain which I never close so I never noticed it was flowering ..This week I have a double flower on it . These bulbs are only sold in shops around xmas time and flower around feb .
when you cut the leaves down it usually reflowers after about 7 weeks, I don't know if that's the flowery way of describing what happens but if you cut the leaves down around April it would be right to be flowering again, you have it a while so you probably know not to leave near apples as that sterilises the bulb and stops any flowering of the plant - amaryliss is a great flower for flower arranging, I used to use it when making up arrangements years ago
They flower in Feb because they are bought as Christmas presents and flower about 6 weeks after planting. Yours s doing what they do naturally which is respond to day length. Once it finishes flowering feed it well, repost it when the leaves die back and you will get lots more flowers next year.