My guess is you are Ticklish, which is why you are here, only you don't know how to release it yet.
Let me explain (and all this applies to me, accepting that other peoples bodies will be completely different), your experience sounds like mine. Namely I have spent my whole life fantasising about tickling and being tickled. Yet I was never even slightly ticklish, and even when I could manufacture a situation to get tickled, I would be as ticklish as a proverbial sack of spanners. Thus I didn't become ticklish until I reached my Thirties (relax you won't have to wait that long), yet now I can make myself as off the scale ticklish as I want to. Part of that was discovering (mainly through the videos of California Star - pre internet) that I wasn't alone in my interest, and that this was a legitimate lifestyle choice, rahther than something to be ashamed about. Beyond that I have discovered THREE SECRETS (again this is what works for me, others will say different) that are able up to turn up my Ticklish volume to ten and beyond.
ONE: 'Avoid Orgasms' - Yes you heard me right. Thus with Tickling being such a sexual thing for me, the longer I go without an orgasm, the more ticklish I become. Thus I end up spending all my time thinking about tickling (which in itself makes you more ticklish), and ones body becomes more and more sensitive as well. There is a whole seperate fetish area connected with orgasm denial, which for me has become as inseperable from ticklishness or enjoying seeing someone tickled, as say nudity might be for someone else. The fact is if I didn't take part in two sports (which involve changing in locker rooms) I would be in a permanent chastity belt.
TWO: 'Laugh When Someone Tries To Tickle You' - Sounds obvious dosen't it, well not really. You see I always used to wait for the tickling to make me laugh, to the extent that I would become more and more frustrated waiting for something to happen, and nothing ever did. Now if someone Tickles me I force myself to laugh, even if I am not feeling any Tickles. You will be surprised firstly how hysterical you can make yourself in a short space of time by forcing yourself to laugh, and then how quickly you can go from not Ticklish, to out of control and unable to recover Ticklish from this self induced hysteria. If you are not sure how to do this, pretend you are a model for FM Concepts.
THREE: 'Practice Tickling Yourself' - Noo this isn't maturbation (if anyones reading this) because on no account do you go near your genitalia (in fact keep it covered up. However a method I have used is two folded over coathangers (one for each hand - duh) with a hankie and chain (or sting with a key) hanging from each, and practice sensitising your whole body area. No this won't make you instantly ticklish. However attempt four to five one hour sessions of this over a period of two weeks (bearing in mind points ONE and TWO above), all the while fantasising about being tickled of course, and you will notice some real progress.
As I say all of the above applies and has worked for me. Other peoples bodies are instantly ticklish (even if they don't want them to be) and will wonder what on earth I am going on about. However hopefully these ideas can unlock your ticklishness, so that next time you are in a real life situation, the fireworks begin.