I’m sure you can find a way to make this one topical to Valentine’s Day, whether you’re feeling optimistic, satisfied, or cynical.
(Ete ni ho wo ageru; “Raise one’s sails to one’s forte”)
Acting when luck gives you a chance to show off your skills. Taking advantage of the opportunity when fate or happenstance plays to your strengths. When the wind blows in your direction, simply raise your sails and ride.
The governing verb here is 揚げる (ageru). Like 上げる and 挙げる (also pronounced ageru), this verb means “to raise,” with the distinction that the character 揚 is often used for things that are hoisted up such as flags, luggage, and ships’ sails. The direct-object marker を (wo) connects the verb to the noun 帆 (ho), “sail.” All that was very straightforward; it’s the last (first, really) little bit that may take some time. The character 得 by itself is “get,” and 手 (te) is “hand,” but putting them together gets you the noun 得手 (ete), indicating someone’s strengths – that is, the things they’re good at. The particle に (ni) seems to be used here in a pseudo-directional sense, since another version replaces 得手 with the more consistently metaphorical 追風 (oikaze or oite), “tailwind.”
As mentioned above, one variant replaces “forte” with “tailwind.” Other variants cut off the verb and end with 帆; others replace the verb with 上げる or even 掛ける (kakeru), “to hang.”
This kotowaza is the え entry in the Edo iroha karuta set, in which the verb may take the classical sentence-final form 揚ぐ (agu).
(“Nani ga tokui ka to kikareru to kimatte suugaku da to kotaeru Yamada-kun dakara, suudoku to naru to, yorokonde ete ni ho wo ageru kamoshirenai to omotte, tanjoubi no purezento de Poketto suudoku wo ageru koto ni shita.”)
[“It’s Yamada, who always says he’s good at math, so I thought that with sudoku he’d probably be really into it since it plays to his strengths, so for his birthday present I’m getting him Pocket Sudoku.”]
PS. I lost about an hour reading Wikipedia articles on sailing terminology while preparing this post. Apparently focusing is not especially an 得手 for me.