Every session is a small deposit. Most practitioners don't see the compound interest because they don't track the deposits. They feel like they're not progressing because the day-to-day is invisible.
When you track every session, you see the curve. You see the weeks you showed up and the weeks you didn't. You see the exact day you crossed your IBJJF time minimum. You see your BJJ Index climbing month by month.
The compound effect in BJJ is real, but only visible with data. Without data, you just feel stuck.