Here, someone realizes they are falling in love, and the poem is built to feel like that realization. The speaker describes the feeling as slow and sure, then adds a twist: it is also "definitely unexpectedly" happening. That phrase is a little funny, since "definitely" and "unexpectedly" seem to pull against each other. It captures how love can feel both certain and like a complete surprise.
The short lines do a lot of work. "Slowly" and "surely" sit on their own, each given a full line, so the reader slows down and moves step by step, almost like the speaker taking careful steps toward something. "And" hangs by itself, a small pause before the longer line arrives. The poem ends on "you," which makes the feeling personal and direct.
The mood is quiet, tender, and a bit shy. There is no big declaration here, just a soft admission, as if the speaker is saying it half to themselves and half to the person they mean.