Is it normal to have young children fall asleep on you?

ok so this has happened to me a couple of times now, so now I wonder if its normal.I am a 21 year old female and when ever i'm around young children like 2-3 years of age they tend to fall asleep on me, even if i havent given them any attention or they havent given me any attention. Once I went to visit family in the US whom I had never met and they had a son, the little boy mostly liked playing with my older brothers and didnt really pay much attention to me, but when he got tired he came over to the couch where i was sitting and climbed on top of me and fell asleep. Just recently i went over to a friends house and they have a 2 year old girl and she said hi and talked to me a bit but stayed mostly around her parents, when it got late and she got sleepy she came over to the couch where i was sitting sat beside me, talked for a bit and fell asleep leaning on me. This has happened several other times and i dont really understand why, i dont want people to think i'm creepy by having children falling asleep on me all the time. So is it normal?