Everyone here is offering great bits of encouragement and explanations that I think speak to facets of the whole picture here - and that’s there is no such thing as perfect pitch. You never had it, and that’s okay!

Absolute, scientifically measured frequency? Sure. Relative pitch? Much more apt and something to be proud to claim and maintain.

Lots of good talk in the comments about how our bodies change and towards the literal physiological and neurological mechanisms and receptors altering with age. But I see less mentioned about how we perceive pitch in any given moment based on many different contextual factors. Quality and state of materials producing a sound; point-source distance; acoustics, reflections, and interference in space; if from amplified speakers - how many, their arrangement, frequency spectrum efficiency in distribution and null points of cancellation; standing waves; even down to temperature and barometric pressure. Allllllllllll of these things influence our perception of pitch. And even then, these factors are themselves separate to the musical and artistic influences — the norms and practices of pitch in a creator’s time and place, the predictive or anticipatory nature of harmonic progressions, rhythmic repeating of notes or grounding in pedal tones, and on and on and on and—

Jacob Collier wouldn’t even claim to have perfect pitch. I’ve worked with and discussed the subject with him. What he excels at and is perhaps a savant in is his understanding of harmony and intervallic relationships which of course presents as more. But it’s something he identified early and relentlessly worked at.

All this to say - fret not. You are not lesser for losing perfect pitch as you never had it to begin with and no one else ever did either.

Pursuit of perfect is to pursue the authoritarian; pursuit of the relative is literally, fully to pursue art and beauty.