I don't think it's wise idea to invest in a coin only by looking the previous ATH, because there's no guarantee the coin will comeback or beat the previous ATH, it's not like Bitcoin.
Doge price was increase because Elon Musk trolled in Twitter and people take it as serious, so many people want to buy Doge. If Elon Musk stop to troll about Doge, Doge price will not increase a lot, just like in 2017/2018.
I think it's just best to leave this kind of troll and not join the current hype about Doge because when you invest with this kind of event going on, you're just gambling with your money and you also need to watch out for the crypto market from time to time because at any moment, the price will crash and the only people will gonna get decent income are the early birds that are fast to sold their Doge at that moment. So it's better to consider the consequences before investing in Doge Coins at the moment and not to be carried away with the ongoing hype.