I'm similar. I only re-read things that I have to, or which are essential. Tbh once I know the guts of a piece, I'll focus on re-reading the important bits – I'm more confident skipping the parts I don't need so much; it's hard to do that on the first read through as it could all be important.

I find that I don't need a schedule of re-reading. It happens almost naturally. Someone will ask a question or I'll be talking about something and need to confirm the source for whatever I'm saying. As the source is familiar, I can (usually quickly) find the right pages, and use the opportunity as a prompt for re-reading.

The same happens with writing: as you try to articulate yourself, you realise what you don't know well enough to explain. Don't bodge it! Take the chance to look it up again and make sure you're right. I wouldn't just routinely re-read stuff.

I do have Capital on my radar to re-read as I know that I can't have understood it properly when I first read it, however much I learned from it, having zero knowledge of dialectics or historical materialism until later, when I started asking, 'okay, so how do I do what he did?' As so much has happened in the meantime, it'll be like reading a different book, I'm sure.

For me, that's the key to re-reading something in full. It doesn't necessarily need a years-long gap, but some internal transformation can make the process more fruitful. This is a bit different to needing to read something twice or more (like a few pages or paras or even a chapter) because it was so difficult/opaque, like some more abstract or technical works can be.