Is it normal for people to "leech" on their friends?

You can only control your own actions. Some leeches can still be good friends, just as long as you don't give them what you aren't willing to part with. The first example "Abbey" sounds like she leeches people dry and then moves on (not particularly fond of that type). The second example "Morgan" sound like you may have been taken by your expectations. You expected more than she became ready to give. Doesn't necessarily mean she's a bad person. Of course, my information is very limited so I am sure I don't know the half of it.

Up to you to decide if you want those people in your life. Taking people as they are and learning to deal with them as such is a decent way to get along. You can't get people to live up to your expectations so why even try? There's people I can find a way to get along with and then there's people I just want out of my life. For the true leeches, it's usually quite as easy as stopping to give them stuff.

Maybe you should see if they are up for a petrol sniffing competition ?

PS: I am a level 13 drug wizard

Forgot to mention. Sometimes I hang with people that I give more to than they give to me and they are still good friends because they give what they can. I don't consider them leeches, they simply have less than I do.

I'll hang out with my friends in strides. It just happens how it happens; I don't plan it. Sometimes I'll be months without seeing somebody and I'll get used to that and then I'll see them a bit more for while... Most people end up getting on my nerves so I need a break is all. Or then sometimes it's them who need a break from me and that's fine to.

I thought a leech was somebody who kept bumming for money and/or stuff like that.

I've had this happen to me, so it is normal (for me). But, looking at the whole, it's not normal, at all, if they were supposedly your best friends.

Abbey Road and Morgan Freeman?

i think too much is invested in this BFF thing, can't you just have a bunch of friends?