The oft-cited example is Proust and his d@#m madeleines. Those sights/smells/things that sometimes unexpectedly but with surety when encountered emotionally transport one back to childhood in a flash.
Letting down the hem on a pant leg (yes, that’s what this odd picture is) recently triggered it for me. In particular the tell-tale white line of the old hem took me back without warning. My mother made dresses/jumpers/pants longer, anticipating an extra season or two of wear by letting down the hems. She covered the scar of the old hem with a trim. I remember a burgundy corduroy jumper with two rows of trim. Money must have really been tight because that hem was no more than a narrow turnback of fabric.
For an instant that fresh-faced child was looking at the ironing board. . . ironically a pair of glasses fitted with progressive lenses sitting right there. Past and present accounted for.
I’ll skip covering up that indelible white line with rick-rack. No need to get carried away with that reliving one’s youth business.