Activation of spells with multiple effects

trashbear

I was lucky enough to pull Seasons Past from a booster, but I don't know if it is behaving as intended. It says:

"The last creature you controlled that died is Returned to your hand.
The last Spell you cast is Returned to your hand.
The last Support you controlled that was destroyed is Returned to your hand.
Convert 15 gems to Green."

I can only cast this spell after I have lost a non-token creature, cast another spell, and lost a support. Is this the intended behavior? Other spells can be cast if not all conditions are met. For example Root Out says:

"Destroy 1 Support gem controlled by your opponent.
Investigate."

I can cast this spell even if my opponent does not control a support.

Are both of these cards behaving as intended or is one bugged?