Science can be a brutal enterprise. Experimental biology is highly prone to failure. Grants are difficult to land. The political climate can make entire nations hostile environments for your research. For those in the trenches of science meant to stem long emergencies, like species conservation, climate change and vaccine development, the emotional costs of the work can be very steep. For long stretches of time, you can give a research question your all, work in obscurity, face continual discouragement and forget why you fought to be in the field in the first place.
…and then there are moments like these, that make you feel like you did the first time your future science touched your heart and soul.