I guess you could take an online IQ test like this one:

IQTest.com

And maybe something like this for memory:

Human Benchmark

The thing is, IQ and memory aren't everything. It often has to do with just how fast you can process information. For example, my IQ is quite high, but I'm not very quick witted. I have to be slow and methodical to work through things. So like I can't remember something that happened very quickly or think quickly in a situation. On the other hand, going step-by-step I can calculated bubble diameter regimes in reactors and things like that.

So what I'm saying is that it probably doesn't have anything to do with your memory or intelligence. Only that you didn't process so much information as fast as the next person. No big deal, just different.