Never be ashamed of what you like regardless of your age. I'm 25. I've played the Pokemon TCG competitively off and on since I was like 12. In more recent years I've played more so because of all the people and friends I've met/made that I don't really see otherwise (namely ones from out of town/state).
My 'full-time job' is ecommerce and my 'part-time job' is youtube and all I sell and make videos of are toys and trading card games. I occasionally get comments along the lines of 'aren't you too old for this' or 'get a life' but I think those people don't realize it's basically my job as well. If/when people know you're making money from it they seem to be more accepting, but that's beside the point. The world/society is too serious...buying/selling/opening/unboxing/reviewing toys helps at least part of me to stay a kid and I enjoy it all. I have fun with it all and have become more and more enthusiastic with my videos. Makes it more fun for me and more entertaining for others to watch too it seems.
Do what you love and don't worry about what some people may think. If it makes you happy, that's good enough!
I now own/operate a YouTube network,
http://ToysMCN.com. Our newest Beyblade videos will be on our network's hub channel,
http://youtube.com/user/toys. Going to try for 1 Beyblade battle on there every 1-2 weeks :-)
Old Unboxings and battles:
http://www.youtube.com/user/Beyblades247