Two suggestions for you:
1. Retype the numbers in the url of the Latest Stream to browse memes from 2, 3 or 4 years ago.
2. Browse some of imgflip's memestreams. There's a list of them here:
imgflip.com/i/l5jxq
Also, there is no limit on submissions to memestreams (however, they can be deleted by the creator of the stream).