Lowered TTL, but still page loads from old IP

[postcd]

Hello, i lowered TTL values in zone file for my domain in hosting account to 600 seconds + changed domain nameservers and its 24 hours and site is still loaded from old server. thats disgusting, please can i debug anyhow why, what is wrong?

Doe it mean that after TTL change, i must visit my site, so my ISP (internet provider) update TTL change or they reload records automatically even noone visit that domain thru them?