Prepare to meet another word that you've been getting wrong forever - we had no idea about this one either. Forte is a great word, it's a flamboyant and fun way to say that you're good at something, or that a particular subject is a strong one for you. However, if you've been going around telling people that the correct pronunciation of words is your "for-tay", then you've been wrong in every sense of the word.
Whilst there is an instance where "for-tay" is acceptable, this related only to its use within the world of music and refers to a composer's note. In the far more common "that's my forte" sense then the 'e' is actually silent, and you should actually be telling people that things are your "fort", exactly how you'd describe a small castle or fortress.