You were Spencer's guardian angel.
After the death of his first love, Maeve, Spencer was never the same. He spiraled downward and downwards until he couldn't get back up again.
He resorted to mindless gambling and his dilaudid addiction. It was horrible to watch. To see a man with so much potential, so much more to give, completely give up.
So, while it was against the sacred rules, you decided to interfere - by turning back the clock before things got too serious with Maeve and stepping in.
It was dangerous, knowing each day spent on earth as a human meant losing your angelic essence and disregarding the sacred laws. But you believed Spencer could do so much more good for the world that it was worth the risk.
You needed a way to infiltrate his life, and knowing everything about him paid off.