If you feel that intense feeling, rather than celebrating, you should probably run away from it, no matter what.
There are, broadly speaking, two reasons why we feel such intense feelings for someone so suddenly: 1 - they remind us of someone or something, even in our childhood and even subconsciously, whom we associate with pleasure or love.
Such association is based on our projection onto that person and it therefore has nothing to do with that person.
Nothing to do with his or her compatibility with us.
We may force ourselves to be compatible with that person for a while for the sake of the intense feeling we are both experiencing, but inevitably it'll lead to disappointment and break ups, or perpetual pain.
2 - it's a biological 'pull' whereby we subconsciously feel we would create healthy children with that person.
This has also nothing to do with compatibility nor the ability to connect and love.
Procreation has nothing to do with the ability to be a great life companion.
It's hard, when you are experiencing such intense feelings, to be objective and you are likely to make haste and wrong decision about that person or about each other.
It is therefore very wise, if you just cannot run away from that person, to be friends for a long time, to truly get to know each other in every aspect, to find out about each other's long-term life goals and emotional needs before jumping to bed with them, and definitely before having children with them or getting married!